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2021-04-22serial: owl: drop low-latency workaroundJohan Hovold
The owl driver has always carried an unnecessary workaround for the infamous low_latency behaviour of tty_flip_buffer_push(), which had been removed years before the driver was added by commit fc60a8b675bd ("tty: serial: owl: Implement console driver"). Specifically, since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-18-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: msm_serial: drop low-latency workaroundJohan Hovold
Commit f77232dab25b ("tty: serial: msm: drop uart_port->lock before calling tty_flip_buffer_push()") claimed to address a locking issue but only provided a dubious lockdep splat from an unrelated driver, which in the end turned out to be due a broken local change carried by the author. Unfortunately these patches were merged before the issue had been analysed properly so the commit messages makes no sense whatsoever. The real issue was first seen on RT which at the time effectively always set the low_latency flag for all serial drivers by patching tty_flip_buffer_push(). This in turn revealed that many drivers did not handle the infamous low_latency behaviour which meant that data was pushed immediately to the line discipline instead of being deferred to a work queue. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/ Cc: Andy Gross <agross@kernel.org> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-17-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: mpc52xx_uart: drop low-latency workaroundJohan Hovold
Commit fbe543b412ce ("Fix a potential issue in mpc52xx uart driver") worked around the infamous low_latency behaviour of tty_flip_buffer_push() by simply dropping and reacquiring the port lock in the interrupt handler. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-16-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: meson: drop low-latency workaroundJohan Hovold
The meson driver has always carried an unnecessary workaround for the infamous low_latency behaviour of tty_flip_buffer_push(), which had already been removed by the time the driver was added by commit ff7693d079e5 ("ARM: meson: serial: add MesonX SoC on-chip uart driver"). Specifically, since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-15-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: mcf: drop low-latency workaroundJohan Hovold
Commit 5275ad70fed3 ("tty: serial: mcf: drop uart_port->lock before calling tty_flip_buffer_push()") claimed to address a locking issue but only provided a dubious lockdep splat from an unrelated driver, which in the end turned out to be due a broken local change carried by the author. Unfortunately these patches were merged before the issue had been analysed properly so the commit messages makes no sense whatsoever. The real issue was first seen on RT which at the time effectively always set the low_latency flag for all serial drivers by patching tty_flip_buffer_push(). This in turn revealed that many drivers did not handle the infamous low_latency behaviour which meant that data was pushed immediately to the line discipline instead of being deferred to a work queue. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/ Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-14-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: lpc32xx_hs: drop low-latency workaroundJohan Hovold
Commit ec128510905c ("tty: serial: lpc32xx_hs: drop uart_port->lock before calling tty_flip_buffer_push()") claimed to address a locking issue but only provided a dubious lockdep splat from an unrelated driver, which in the end turned out to be due a broken local change carried by the author. Unfortunately these patches were merged before the issue had been analysed properly so the commit messages makes no sense whatsoever. The real issue was first seen on RT which at the time effectively always set the low_latency flag for all serial drivers by patching tty_flip_buffer_push(). This in turn revealed that many drivers did not handle the infamous low_latency behaviour which meant that data was pushed immediately to the line discipline instead of being deferred to a work queue. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/ Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-13-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: icom: drop low-latency workaroundJohan Hovold
Commit 5faf75d7fed2 ("tty: serial: icom: drop uart_port->lock before calling tty_flip_buffer_push()") claimed to address a locking issue but only provided a dubious lockdep splat from an unrelated driver, which in the end turned out to be due a broken local change carried by the author. Unfortunately these patches were merged before the issue had been analysed properly so the commit messages makes no sense whatsoever. The real issue was first seen on RT which at the time effectively always set the low_latency flag for all serial drivers by patching tty_flip_buffer_push(). This in turn revealed that many drivers did not handle the infamous low_latency behaviour which meant that data was pushed immediately to the line discipline instead of being deferred to a work queue. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/ Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-12-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: bcm63xx: drop low-latency workaroundJohan Hovold
Commit b4d499241c34 ("tty: serial: bcm63xx: drop uart_port->lock before calling tty_flip_buffer_push()") claimed to address a locking issue but only provided a dubious lockdep splat from an unrelated driver, which in the end turned out to be due a broken local change carried by the author. Unfortunately these patches were merged before the issue had been analysed properly so the commit messages makes no sense whatsoever. The real issue was first seen on RT which at the time effectively always set the low_latency flag for all serial drivers by patching tty_flip_buffer_push(). This in turn revealed that many drivers did not handle the infamous low_latency behaviour which meant that data was pushed immediately to the line discipline instead of being deferred to a work queue. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/ Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-11-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: atmel_serial: drop low-latency workaroundJohan Hovold
Commit 1ecc26bd2789 ("atmel_serial: split the interrupt handler") worked around the infamous low_latency behaviour of tty_flip_buffer_push() by dropping and reacquiring the port lock in the tasklet callback. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Cc: Richard Genoud <richard.genoud@gmail.com> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-10-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: arc_uart: drop low-latency workaroundJohan Hovold
Commit 3fa1200851c7 ("tty: serial: arc: drop uart_port->lock before calling tty_flip_buffer_push()") claimed to address a locking issue but only provided a dubious lockdep splat from an unrelated driver, which in the end turned out to be due a broken local change carried by the author. Unfortunately these patches were merged before the issue had been analysed properly so the commit messages makes no sense whatsoever. The real issue was first seen on RT which at the time effectively always set the low_latency flag for all serial drivers by patching tty_flip_buffer_push(). This in turn revealed that many drivers did not handle the infamous low_latency behaviour which meant that data was pushed immediately to the line discipline instead of being deferred to a work queue. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/ Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-9-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: ar933x: drop low-latency workaroundJohan Hovold
Commit b16c8e3eed12 ("tty: serial: ar933x: drop uart_port->lock before calling tty_flip_buffer_push()") claimed to address a locking issue but only provided a dubious lockdep splat from an unrelated driver, which in the end turned out to be due a broken local change carried by the author. Unfortunately these patches were merged before the issue had been analysed properly so the commit messages makes no sense whatsoever. The real issue was first seen on RT which at the time effectively always set the low_latency flag for all serial drivers by patching tty_flip_buffer_push(). This in turn revealed that many drivers did not handle the infamous low_latency behaviour which meant that data was pushed immediately to the line discipline instead of being deferred to a work queue. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/ Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-8-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: apbuart: drop low-latency workaroundJohan Hovold
Commit 78d34d75c84d ("tty: serial: apbuart: drop uart_port->lock before calling tty_flip_buffer_push()") claimed to address a locking issue but only provided a dubious lockdep splat from an unrelated driver, which in the end turned out to be due a broken local change carried by the author. Unfortunately these patches were merged before the issue had been analysed properly so the commit messages makes no sense whatsoever. The real issue was first seen on RT which at the time effectively always set the low_latency flag for all serial drivers by patching tty_flip_buffer_push(). This in turn revealed that many drivers did not handle the infamous low_latency behaviour which meant that data was pushed immediately to the line discipline instead of being deferred to a work queue. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/ Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-7-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: amba-pl011: drop low-latency workaroundJohan Hovold
Commit ead76f329f77 ("ARM: 6763/1: pl011: add optional RX DMA to PL011 v2") added RX DMA support and also reproduced the workaround for the infamous low_latency behaviour of tty_flip_buffer_push() by dropping and reacquiring the port lock during receive processing. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Note that the port lock is also dropped in the PIO path (see pl011_rx_chars), but it is not clear whether this is still needed by the DMA code added by the aforementioned commit. Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Russell King <linux@armlinux.org.uk> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-6-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: amba-pl010: drop low-latency workaroundJohan Hovold
Commit 2389b272168c ("[ARM] 4417/1: Serial: Fix AMBA drivers locking") worked around the infamous low_latency behaviour of tty_flip_buffer_push() by simply dropping and reacquiring the port lock in the interrupt handler. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Cc: Russell King <linux@armlinux.org.uk> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-5-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: altera_uart: drop low-latency workaroundJohan Hovold
Commit dd085ed8ef6c ("tty: serial: altera: drop uart_port->lock before calling tty_flip_buffer_push()") claimed to address a locking issue but only provided a dubious lockdep splat from an unrelated driver, which in the end turned out to be due a broken local change carried by the author. Unfortunately these patches were merged before the issue had been analysed properly so the commit messages makes no sense whatsoever. The real issue was first seen on RT which at the time effectively always set the low_latency flag for all serial drivers by patching tty_flip_buffer_push(). This in turn revealed that many drivers did not handle the infamous low_latency behaviour which meant that data was pushed immediately to the line discipline instead of being deferred to a work queue. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/ Cc: Tobias Klauser <tklauser@distanz.ch> Acked-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-4-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: altera_jtaguart: drop low-latency workaroundJohan Hovold
Commit 53dd0ba7a6f4 ("tty: serial: altera_jtag: drop uart_port->lock before calling tty_flip_buffer_push()") claimed to address a locking issue but only provided a dubious lockdep splat from an unrelated driver, which in the end turned out to be due a broken local change carried by the author. Unfortunately these patches were merged before the issue had been analysed properly so the commit messages makes no sense whatsoever. The real issue was first seen on RT which at the time effectively always set the low_latency flag for all serial drivers by patching tty_flip_buffer_push(). This in turn revealed that many drivers did not handle the infamous low_latency behaviour which meant that data was pushed immediately to the line discipline instead of being deferred to a work queue. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/ Cc: Tobias Klauser <tklauser@distanz.ch> Acked-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-3-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22tty: mxser: drop low-latency workaroundJohan Hovold
Commit 67d2bc58afdd ("Char: mxser_new, fix recursive locking") worked around the infamous low_latency behaviour of tty_flip_buffer_push() by simply dropping and reacquiring the port lock in the interrupt handler. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Link: https://lore.kernel.org/lkml/3018694794025219@wsc.cz/T/#m06b04c640a7b6f41afb3d34a4cf29b1df4935d3a Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-2-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: omap: fix rs485 half-duplex filteringDario Binacchi
Data received during half-duplex transmission must be filtered. If the target device responds quickly, emptying the FIFO at the end of the transmission can erase not only the echo characters but also part of the response message. By keeping the receive interrupt enabled even during transmission, it allows you to filter each echo character and only in a number equal to those transmitted. The issue was generated by a target device that started responding 240us later having received a request in communication at 115200bps. Sometimes, some messages received by the target were missing some of the first bytes. Fixes: 3a13884abea0 ("tty/serial: omap: empty the RX FIFO at the end of half-duplex TX") Signed-off-by: Dario Binacchi <dariobin@libero.it> Link: https://lore.kernel.org/r/20210418094705.27014-1-dariobin@libero.it Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: omap: don't disable rs485 if rts gpio is missingDario Binacchi
There are rs485 transceivers (e.g. MAX13487E/MAX13488E) which automatically disable or enable the driver and receiver to keep the bus in the correct state. In these cases we don't need a GPIO for flow control. Fixes: 4a0ac0f55b18 ("OMAP: add RS485 support") Signed-off-by: Dario Binacchi <dariobin@libero.it> Link: https://lore.kernel.org/r/20210415210945.25863-1-dariobin@libero.it Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: stm32: defer sysrq processingJohan Hovold
Use the uart_unlock_and_check_sysrq() helper to defer sysrq processing until receive processing is done and the port lock has been released. This allows cleaning up the console_write() implementation by not having to work around the recursive sysrq case (by dropping locking completely) and also makes the console code work with PREEMPT_RT by no longer relying on local_irq_save(). Reviewed-by: Valentin Caron<valentin.caron@foss.st.com> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210416140557.25177-4-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: stm32: fix threaded interrupt handlingJohan Hovold
When DMA is enabled the receive handler runs in a threaded handler, but the primary handler up until very recently neither disabled interrupts in the device or used IRQF_ONESHOT. This would lead to a deadlock if an interrupt comes in while the threaded receive handler is running under the port lock. Commit ad7676812437 ("serial: stm32: fix a deadlock condition with wakeup event") claimed to fix an unrelated deadlock, but unfortunately also disabled interrupts in the threaded handler. While this prevents the deadlock mentioned in the previous paragraph it also defeats the purpose of using a threaded handler in the first place. Fix this by making the interrupt one-shot and not disabling interrupts in the threaded handler. Note that (receive) DMA must not be used for a console port as the threaded handler could be interrupted while holding the port lock, something which could lead to a deadlock in case an interrupt handler ends up calling printk. Fixes: ad7676812437 ("serial: stm32: fix a deadlock condition with wakeup event") Fixes: 3489187204eb ("serial: stm32: adding dma support") Cc: stable@vger.kernel.org # 4.9 Cc: Alexandre TORGUE <alexandre.torgue@st.com> Cc: Gerald Baeza <gerald.baeza@st.com> Reviewed-by: Valentin Caron<valentin.caron@foss.st.com> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210416140557.25177-3-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: do not restore interrupt state in sysrq helperJohan Hovold
The uart_unlock_and_check_sysrq() helper can be used to defer processing of sysrq until the interrupt handler has released the port lock and is about to return. Since commit 81e2073c175b ("genirq: Disable interrupts for force threaded handlers") interrupt handlers that are not explicitly requested as threaded are always called with interrupts disabled and there is no need to save the interrupt state when taking the port lock. Instead of adding another sysrq helper for when the interrupt state has not needlessly been saved, drop the state parameter from uart_unlock_and_check_sysrq() and update its callers to no longer explicitly disable interrupts in their interrupt handlers. Cc: Joel Stanley <joel@jms.id.au> Cc: Andrew Jeffery <andrew@aj.id.au> Cc: Andy Gross <agross@kernel.org> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210416140557.25177-2-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22tty: synclink_gt: remove redundant initialization of variable countColin Ian King
The variable count is being initialized with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Colin Ian King <colin.king@canonical.com> Addresses-Coverity: ("Unused value") Link: https://lore.kernel.org/r/20210420105718.377086-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22ttyprintk: Add TTY hangup callback.Tetsuo Handa
syzbot is reporting hung task due to flood of tty_warn(tty, "%s: tty->count = 1 port count = %d\n", __func__, port->count); message [1], for ioctl(TIOCVHANGUP) prevents tty_port_close() from decrementing port->count due to tty_hung_up_p() == true. ---------- #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <sys/ioctl.h> #include <unistd.h> int main(int argc, char *argv[]) { int i; int fd[10]; for (i = 0; i < 10; i++) fd[i] = open("/dev/ttyprintk", O_WRONLY); ioctl(fd[0], TIOCVHANGUP); for (i = 0; i < 10; i++) close(fd[i]); close(open("/dev/ttyprintk", O_WRONLY)); return 0; } ---------- When TTY hangup happens, port->count needs to be reset via "struct tty_operations"->hangup callback. [1] https://syzkaller.appspot.com/bug?id=39ea6caa479af471183997376dc7e90bc7d64a6a Reported-by: syzbot <syzbot+43e93968b964e369db0b@syzkaller.appspotmail.com> Reported-by: syzbot <syzbot+3ed715090790806d8b18@syzkaller.appspotmail.com> Tested-by: syzbot <syzbot+43e93968b964e369db0b@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Fixes: 24b4b67d17c308aa ("add ttyprintk driver") Link: https://lore.kernel.org/r/17e0652d-89b7-c8c0-fb53-e7566ac9add4@i-love.sakura.ne.jp Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: dwc3: core: Do core softreset when switch modeYu Chen
From: John Stultz <john.stultz@linaro.org> According to the programming guide, to switch mode for DRD controller, the driver needs to do the following. To switch from device to host: 1. Reset controller with GCTL.CoreSoftReset 2. Set GCTL.PrtCapDir(host mode) 3. Reset the host with USBCMD.HCRESET 4. Then follow up with the initializing host registers sequence To switch from host to device: 1. Reset controller with GCTL.CoreSoftReset 2. Set GCTL.PrtCapDir(device mode) 3. Reset the device with DCTL.CSftRst 4. Then follow up with the initializing registers sequence Currently we're missing step 1) to do GCTL.CoreSoftReset and step 3) of switching from host to device. John Stult reported a lockup issue seen with HiKey960 platform without these steps[1]. Similar issue is observed with Ferry's testing platform[2]. So, apply the required steps along with some fixes to Yu Chen's and John Stultz's version. The main fixes to their versions are the missing wait for clocks synchronization before clearing GCTL.CoreSoftReset and only apply DCTL.CSftRst when switching from host to device. [1] https://lore.kernel.org/linux-usb/20210108015115.27920-1-john.stultz@linaro.org/ [2] https://lore.kernel.org/linux-usb/0ba7a6ba-e6a7-9cd4-0695-64fc927e01f1@gmail.com/ Fixes: 41ce1456e1db ("usb: dwc3: core: make dwc3_set_mode() work properly") Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Ferry Toth <fntoth@gmail.com> Cc: Wesley Cheng <wcheng@codeaurora.org> Cc: <stable@vger.kernel.org> Tested-by: John Stultz <john.stultz@linaro.org> Tested-by: Wesley Cheng <wcheng@codeaurora.org> Signed-off-by: Yu Chen <chenyu56@huawei.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com> Link: https://lore.kernel.org/r/374440f8dcd4f06c02c2caf4b1efde86774e02d9.1618521663.git.Thinh.Nguyen@synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: dwc2: Get rid of useless error checks in suspend interruptArtur Petrosyan
Squashed from Douglas Anderson's suggested commit "usb: dwc2: Get rid of useless error checks for hibernation/partial power down" - After this commit there should never be any case where dwc2_enter_partial_power_down() and dwc2_enter_hibernation() are called when 'params.power_down' is not correct. Get rid of the pile of error checking. - As part of this cleanup some of the error messages not to have __func__ in them. That's not needed for dev_err() calls since they already have the device name as part of the message. Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com> Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20210416124843.9EDCDA005D@mailhost.synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: dwc2: Update dwc2_handle_usb_suspend_intr function.Artur Petrosyan
To avoid working in two modes (partial power down and hibernation) changed conditions for entering partial power down or hibernation. Instead of checking hw_params.power_optimized and hw_params.hibernation now checking power_down param which already set to one of the options (Hibernation or Partial Power Down) based on OTG_EN_PWROPT. Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com> Signed-off-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Link: https://lore.kernel.org/r/20210416124835.9F257A005D@mailhost.synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: dwc2: Add exit hibernation mode before removing driveArtur Petrosyan
When dwc2 core is in hibernation mode loading driver again causes driver fail. Because in that mode registers are not accessible. In order to exit from hibernation checking dwc2 core power saving state in "dwc2_driver_remove()" function. If core is in hibernation, then checking the operational mode of the driver. To check whether dwc2 core is operating in host mode or device mode there is one way which is retrieving the backup value of "gotgctl" and compare the "CurMod" value. If previously core entered hibernation in host mode then the exit is performed for host if not then exit is performed for device mode. The introduced checking is because in hibernation state all registers are not accessible. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com> Link: https://lore.kernel.org/r/20210416124827.9BB59A005D@mailhost.synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: dwc2: Add hibernation exiting flow by system resumeArtur Petrosyan
Adds a new flow of exiting hibernation when PC is resumed from suspend state. Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com> Link: https://lore.kernel.org/r/20210416124819.A3B26A005C@mailhost.synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: dwc2: Add hibernation entering flow by system suspendArtur Petrosyan
Adds a new flow of entering hibernation when PC is hibernated or suspended. Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com> Link: https://lore.kernel.org/r/20210416124811.BBFDBA005C@mailhost.synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: dwc2: Allow exit hibernation in urb enqueueArtur Petrosyan
When core is in hibernation state and an external hub is connected, upper layer sends URB enqueue request, which results in port reset issue. - Added exit from hibernation state to avoid port reset issue and process upper layer request properly. Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com> Link: https://lore.kernel.org/r/20210416124803.D1C1FA005F@mailhost.synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: dwc2: Move exit hibernation to dwc2_port_resume() functionArtur Petrosyan
This move is done to call hibernation exit handler in "dwc2_port_resume()" function when core receives port resume. Otherwise it could be confusing to exit hibernation in "dwc2_hcd_hub_control()" function but other power saving modes in "dwc2_port_resume()" function. Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com> Link: https://lore.kernel.org/r/20210416124755.E47F3A005D@mailhost.synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: dwc2: Move enter hibernation to dwc2_port_suspend() functionArtur Petrosyan
This move is done to call enter hibernation handler in "dwc2_port_suspend()" function when core receives port suspend. Otherwise it could be confusing to enter to hibernation in "dwc2_hcd_hub_control()" function but other power saving modes in "dwc2_port_suspend()" function. Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com> Link: https://lore.kernel.org/r/20210416124747.EE79EA005C@mailhost.synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: dwc2: Clear GINTSTS_RESTOREDONE bit after restore is generated.Artur Petrosyan
When hibernation exit is performed the dwc2_hib_restore_common() function is called. In that function we wait until GINTSTS_RESTOREDONE bit is set. However, after the setting of that bit we get a lot of (dwc2_hsotg_irq:) interrupts which indicates that (GINTSTS.RstrDoneInt) restore done interrupt is asserted. To avoid restore done interrupt storm after restore is generated clear GINTSTS_RESTOREDONE bit in GINTSTS register. Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com> Link: https://lore.kernel.org/r/20210416124739.D6269A005D@mailhost.synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: dwc2: Clear fifo_map when resetting core.Artur Petrosyan
Switching from device mode to host mode by disconnecting device cable core enters and exits form hibernation. However, the fifo map remains not cleared. It results to a WARNING (WARNING: CPU: 5 PID: 0 at drivers/usb/dwc2/ gadget.c:307 dwc2_hsotg_init_fifo+0x12/0x152 [dwc2]) if in host mode we disconnect the micro a to b host cable. Because core reset occurs. To avoid the WARNING, fifo_map should be cleared in dwc2_core_reset() function by taking into account configs. fifo_map must be cleared only if driver is configured in "CONFIG_USB_DWC2_PERIPHERAL" or "CONFIG_USB_DWC2_DUAL_ROLE" mode. - Added "static inline void dwc2_clear_fifo_map()" helper function to clear fifo_map with peripheral or dual role mode. - Added a dummy version of "dwc2_clear_fifo_map()" helper for host-only mode. Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com> Link: https://lore.kernel.org/r/20210416124731.C500AA005D@mailhost.synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: dwc2: Allow exiting hibernation from gpwrdn rst detectArtur Petrosyan
When device cable is disconnected core receives suspend interrupt and enters hibernation. After entering into hibernation GPWRDN_RST_DET and GPWRDN_STS_CHGINT interrupts are asserted. Allowed exit from gadget hibernation from GPWRDN_RST_DET by checking only linestate. Changed the return type of "dwc2_handle_gpwrdn_intr()" function from void to int because exit from hibernation functions have a return value. Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com> Link: https://lore.kernel.org/r/20210416124723.B6F17A005C@mailhost.synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: dwc2: Fix hibernation between host and device modes.Artur Petrosyan
When core is in hibernation in host mode and a device cable was connected then driver exited from device hibernation. However, registers saved for host mode and when exited from device hibernation register restore would be done for device register which was wrong because there was no device registers stored to restore. - Added dwc_handle_gpwrdn_disc_det() function which handles gpwrdn disconnect detect flow and exits hibernation without restoring the registers. - Updated exiting from hibernation in GPWRDN_STS_CHGINT with calling dwc_handle_gpwrdn_disc_det() function. Here no register is restored which is the solution described above. Fixes: 65c9c4c6b01f ("usb: dwc2: Add dwc2_handle_gpwrdn_intr() handler") Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com> Signed-off-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Link: https://lore.kernel.org/r/20210416124715.75355A005D@mailhost.synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: dwc2: Fix host mode hibernation exit with remote wakeup flow.Artur Petrosyan
Added setting "port_connect_status_change" flag to "1" in order to re-enumerate, because after exit from hibernation port connection status is not detected. Fixes: c5c403dc4336 ("usb: dwc2: Add host/device hibernation functions") Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com> Link: https://lore.kernel.org/r/20210416124707.5EEC2A005D@mailhost.synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: dwc2: Reset DEVADDR after exiting gadget hibernation.Artur Petrosyan
Initially resetting device address was done in dwc2_hsotg_irq() interrupt handler. However, when core is hibernated USB RESET is not handled in dwc2_hsotg_irq() handler, instead USB RESET interrupt is handled in dwc2_handle_gpwrdn_intr() handler. - Added reset device address to zero when core exits from gadget hibernation. Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com> Signed-off-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Link: https://lore.kernel.org/r/20210416124659.652CFA005C@mailhost.synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: dwc2: Update exit hibernation when port reset is assertedArtur Petrosyan
No need to check for "DWC2_POWER_DOWN_PARAM_HIBERNATION" param as "hsotg->hibernated" flag is already enough for exiting from hibernation mode. - Removes checking of "DWC2_POWER_DOWN_PARAM_HIBERNATION" param. - For code readability Hibernation exit code moved after debug message print. - Added "dwc2_exit_hibernation()" function error checking. Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com> Link: https://lore.kernel.org/r/20210416124651.51C8DA005C@mailhost.synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22Merge tag 'usb-serial-5.13-rc1' of ↵Greg Kroah-Hartman
https://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial into usb-next Johan writes: USB-serial updates for 5.13-rc1 Here are the USB-serial updates for 5.13-rc1, including: - better type detection for pl2303 - support for more line speeds for pl2303 (TA/TB) - fixed CSIZE handling for the new xr driver - core support for multi-interface functions - TIOCGSERIAL and TIOCSSERIAL fixes - generic TIOCSSERIAL support (e.g. for closing_wait) - fixed return value for unsupported ioctls - support for gpio valid masks in cp210x - drain-delay fixes and improvements - support for multi-port devices for xr - generalisation of the xr driver to support three new device classes (XR21B142X, XR21B1411 and XR2280X) Included are also various clean ups. All have been in linux-next with no reported issues. * tag 'usb-serial-5.13-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial: (72 commits) USB: cdc-acm: add more Maxlinear/Exar models to ignore list USB: serial: xr: add copyright notice USB: serial: xr: reset FIFOs on open USB: serial: xr: add support for XR22801, XR22802, XR22804 USB: serial: xr: add support for XR21B1411 USB: serial: xr: add support for XR21B1421, XR21B1422 and XR21B1424 USB: serial: xr: add type abstraction USB: serial: xr: drop type prefix from shared defines USB: serial: xr: move pin configuration to probe USB: serial: xr: rename GPIO-pin defines USB: serial: xr: rename GPIO-mode defines USB: serial: xr: add support for XR21V1412 and XR21V1414 USB: serial: ti_usb_3410_5052: clean up termios CSIZE handling USB: serial: ti_usb_3410_5052: use kernel types consistently USB: serial: ti_usb_3410_5052: add port-command helpers USB: serial: ti_usb_3410_5052: clean up vendor-request helpers USB: serial: ti_usb_3410_5052: drop unnecessary packed attributes USB: serial: io_ti: drop unnecessary packed attributes USB: serial: io_ti: use kernel types consistently USB: serial: io_ti: add read-port-command helper ...
2021-04-22usb: dwc3: gadget: Remove FS bInterval_m1 limitationThinh Nguyen
The programming guide incorrectly stated that the DCFG.bInterval_m1 must be set to 0 when operating in fullspeed. There's no such limitation for all IPs. See DWC_usb3x programming guide section 3.2.2.1. Fixes: a1679af85b2a ("usb: dwc3: gadget: Fix setting of DEPCFG.bInterval_m1") Cc: <stable@vger.kernel.org> Acked-by: Felipe Balbi <balbi@kernel.org> Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com> Link: https://lore.kernel.org/r/5d4139ae89d810eb0a2d8577fb096fc88e87bfab.1618472454.git.Thinh.Nguyen@synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: xhci-mtk: remove bus status checkChunfeng Yun
PM will take care of the status of child device, so no need check each port anymore. Suggested-by: Ikjoon Jang <ikjn@chromium.org> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com> Link: https://lore.kernel.org/r/1618555706-6810-1-git-send-email-chunfeng.yun@mediatek.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22dt-bindings: connector: Add slow-charger-loop definitionBadhri Jagan Sridharan
Allows PMIC charger loops which are slow(i.e. cannot meet the 15ms deadline) to still comply to pSnkStby i.e Maximum power that can be consumed by sink while in Sink Standby state as defined in 7.4.2 Sink Electrical Parameters of USB Power Delivery Specification Revision 3.0, Version 1.2. This patch introduces slow-charger-loop which when set makes the port request PD_P_SNK_STDBY_MW(2.5W i.e 500mA@5V) upon entering SNK_DISCOVERY (instead of 3A or the 1.5A during SNK_DISCOVERY) and the actual currrent limit after RX of PD_CTRL_PSRDY for PD link or during SNK_READY for non-pd link. Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Badhri Jagan Sridharan <badhri@google.com> Link: https://lore.kernel.org/r/20210414142656.63749-3-badhri@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: dwc2: Enable RPi in ACPI modeJeremy Linton
The dwc2 driver has everything we need to run in ACPI mode except for the ACPI module device table boilerplate. With that added and identified as "BCM2848", an id in use by other OSs for this device, the dw2 controller on the BCM2711 will work. Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Link: https://lore.kernel.org/r/20210413215834.3126447-2-jeremy.linton@arm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22dt-bindings: usb: dwc3: Add disabling LPM for gadgetThinh Nguyen
Add a new DT option to disable LPM for gadget and update the description for usb2-lpm-disable related to host for clarity. Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com> Link: https://lore.kernel.org/r/f31348ba744318c83b3a9ab1eab75c61122b15ae.1618366071.git.Thinh.Nguyen@synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22USB: CDC-ACM: fix poison/unpoison imbalanceOliver Neukum
suspend() does its poisoning conditionally, resume() does it unconditionally. On a device with combined interfaces this will balance, on a device with two interfaces the counter will go negative and resubmission will fail. Both actions need to be done conditionally. Fixes: 6069e3e927c8f ("USB: cdc-acm: untangle a circular dependency between callback and softint") Signed-off-by: Oliver Neukum <oneukum@suse.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210421074513.4327-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22USB: Add reset-resume quirk for WD19's Realtek HubChris Chiu
Realtek Hub (0bda:5487) in Dell Dock WD19 sometimes fails to work after the system resumes from suspend with remote wakeup enabled device connected: [ 1947.640907] hub 5-2.3:1.0: hub_ext_port_status failed (err = -71) [ 1947.641208] usb 5-2.3-port5: cannot disable (err = -71) [ 1947.641401] hub 5-2.3:1.0: hub_ext_port_status failed (err = -71) [ 1947.641450] usb 5-2.3-port4: cannot reset (err = -71) Information of this hub: T: Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 10 Spd=480 MxCh= 5 D: Ver= 2.10 Cls=09(hub ) Sub=00 Prot=02 MxPS=64 #Cfgs= 1 P: Vendor=0bda ProdID=5487 Rev= 1.47 S: Manufacturer=Dell Inc. S: Product=Dell dock C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr= 0mA I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=01 Driver=hub E: Ad=81(I) Atr=03(Int.) MxPS= 1 Ivl=256ms I:* If#= 0 Alt= 1 #EPs= 1 Cls=09(hub ) Sub=00 Prot=02 Driver=hub E: Ad=81(I) Atr=03(Int.) MxPS= 1 Ivl=256ms The failure results from the ETIMEDOUT by chance when turning on the suspend feature for the specified port of the hub. The port seems to be in an unknown state so the hub_activate during resume fails the hub_port_status, then the hub will fail to work. The quirky hub needs the reset-resume quirk to function correctly. Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Chris Chiu <chris.chiu@canonical.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210420174651.6202-1-chris.chiu@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: gadget: net2272: remove redundant initialization of statusColin Ian King
The variable status is being initialized with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed and move the declaration of status to the scope where it is used. Signed-off-by: Colin Ian King <colin.king@canonical.com> Addresses-Coverity: ("Unused value") Link: https://lore.kernel.org/r/20210420110622.377339-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22usb: storage: datafab: remove redundant assignment of variable resultColin Ian King
The variable result is being assigned with a value that is never read, the assignment is redundant and can be removed. Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Colin Ian King <colin.king@canonical.com> Addresses-Coverity: ("Unused value") Link: https://lore.kernel.org/r/20210420113818.378478-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>