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path: root/drivers/tty/serial/xilinx_uartps.c
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2025-02-18serial: xilinx_uartps: Use helper function hrtimer_update_function()Nam Cao
The field 'function' of struct hrtimer should not be changed directly, as the write is lockless and a concurrent timer expiry might end up using the wrong function pointer. Switch to use hrtimer_update_function() which also performs runtime checks that it is safe to modify the callback. Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/af7823518fb060c6c97105a2513cfc61adbdf38f.1738746927.git.namcao@linutronix.de
2025-02-18serial: xilinx_uartps: Switch to use hrtimer_setup()Nam Cao
hrtimer_setup() takes the callback function pointer as argument and initializes the timer completely. Replace hrtimer_init() and the open coded initialization of hrtimer::function with the new setup mechanism. Patch was created by using Coccinelle. Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Zack Rusin <zack.rusin@broadcom.com> Link: https://lore.kernel.org/all/4a028a23126b3350a5e243dcb49e1ef1b2a4b740.1738746904.git.namcao@linutronix.de
2025-01-13tty: xilinx_uartps: split sysrq handlingSean Anderson
lockdep detects the following circular locking dependency: CPU 0 CPU 1 ========================== ============================ cdns_uart_isr() printk() uart_port_lock(port) console_lock() cdns_uart_console_write() if (!port->sysrq) uart_port_lock(port) uart_handle_break() port->sysrq = ... uart_handle_sysrq_char() printk() console_lock() The fixed commit attempts to avoid this situation by only taking the port lock in cdns_uart_console_write if port->sysrq unset. However, if (as shown above) cdns_uart_console_write runs before port->sysrq is set, then it will try to take the port lock anyway. This may result in a deadlock. Fix this by splitting sysrq handling into two parts. We use the prepare helper under the port lock and defer handling until we release the lock. Fixes: 74ea66d4ca06 ("tty: xuartps: Improve sysrq handling") Signed-off-by: Sean Anderson <sean.anderson@linux.dev> Cc: stable@vger.kernel.org # c980248179d: serial: xilinx_uartps: Use port lock wrappers Acked-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20250110213822.2107462-1-sean.anderson@linux.dev Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-11serial: Switch back to struct platform_driver::remove()Uwe Kleine-König
After commit 0edb555a65d1 ("platform: Make platform_driver::remove() return void") .remove() is (again) the right callback to implement for platform drivers. Convert all platform drivers below drivers/tty/serial to use .remove(), with the eventual goal to drop struct platform_driver::remove_new(). As .remove() and .remove_new() have the same prototypes, conversion is done by just changing the structure member name in the driver initializer. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> Link: https://lore.kernel.org/r/20241007205803.444994-7-u.kleine-koenig@baylibre.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-03serial: xilinx_uartps: Make cdns_rs485_supported staticJinjie Ruan
The sparse tool complains as follows: drivers/tty/serial/xilinx_uartps.c:222:21: warning: symbol 'cdns_rs485_supported' was not declared. Should it be static? This symbol is not used outside xilinx_uartps.c, so marks it static. Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Link: https://lore.kernel.org/r/20240819120107.3884973-1-ruanjinjie@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-04tty: serial: uartps: Add support for uartps controller resetManikanta Guntupalli
Add support for an optional reset for the uartps controller using the reset driver. If the uartps node contains the "resets" property, then cdns_uart_startup performs uartps controller non-pulse out of reset and reset in exit path. Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com> Link: https://lore.kernel.org/r/20240425062358.1347684-4-manikanta.guntupalli@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-09tty: serial: switch from circ_buf to kfifoJiri Slaby (SUSE)
Switch from struct circ_buf to proper kfifo. kfifo provides much better API, esp. when wrap-around of the buffer needs to be taken into account. Look at pl011_dma_tx_refill() or cpm_uart_tx_pump() changes for example. Kfifo API can also fill in scatter-gather DMA structures, so it easier for that use case too. Look at lpuart_dma_tx() for example. Note that not all drivers can be converted to that (like atmel_serial), they handle DMA specially. Note that usb-serial uses kfifo for TX for ages. omap needed a bit more care as it needs to put a char into FIFO to start the DMA transfer when OMAP_DMA_TX_KICK is set. In that case, we have to do kfifo_dma_out_prepare twice: once to find out the tx_size (to find out if it is worths to do DMA at all -- size >= 4), the second time for the actual transfer. All traces of circ_buf are removed from serial_core.h (and its struct uart_state). Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Cc: Al Cooper <alcooperx@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Cc: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com> Cc: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Nicolas Ferre <nicolas.ferre@microchip.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Claudiu Beznea <claudiu.beznea@tuxon.dev> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: Maciej W. Rozycki <macro@orcam.me.uk> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: Neil Armstrong <neil.armstrong@linaro.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Jerome Brunet <jbrunet@baylibre.com> Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Cc: Taichi Sugaya <sugaya.taichi@socionext.com> Cc: Takao Orito <orito.takao@socionext.com> Cc: Bjorn Andersson <andersson@kernel.org> Cc: Konrad Dybcio <konrad.dybcio@linaro.org> Cc: Pali Rohár <pali@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Cc: Alim Akhtar <alim.akhtar@samsung.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Orson Zhai <orsonzhai@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: Patrice Chotard <patrice.chotard@foss.st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: David S. Miller <davem@davemloft.net> Cc: Hammer Hsieh <hammerh0314@gmail.com> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@kernel.org> Cc: Michal Simek <michal.simek@amd.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Christian König <christian.koenig@amd.com> Link: https://lore.kernel.org/r/20240405060826.2521-13-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: serial: uartps: Add rs485 support to uartps driverManikanta Guntupalli
Add rs485 support to uartps driver. Use either rts-gpios or RTS to control RS485 phy as driver or a receiver. Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com> Link: https://lore.kernel.org/r/20240123061655.2150946-4-manikanta.guntupalli@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: serial: uartps: Relocate cdns_uart_tx_empty to facilitate rs485Manikanta Guntupalli
Relocate cdns_uart_tx_empty function to avoid prototype statement in rs485 changes. Update return check with uart_tx_stopped() in cdns_uart_handle_tx(). Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com> Link: https://lore.kernel.org/r/20240123061655.2150946-3-manikanta.guntupalli@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-25serial: xilinx_uartps: Fix kernel doc about .remove()'s return codeUwe Kleine-König
Since the driver was converted to use .remove_new() the return function doesn't return a value any more. So remove the obsolete documentation about the return value. Reported-by: Michal Simek <michal.simek@amd.com> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Michal Simek <michal.simek@amd.com> Link: https://lore.kernel.org/r/20231117101236.878008-1-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-23serial: xilinx_uartps: Convert to platform remove callback returning voidUwe Kleine-König
The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20231110152927.70601-53-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-16serial: xilinx_uartps: unset STOPBRK when setting STARTBRKJulien Malik
Zynq UG585 states, in chapter B.33, for XUARTPS_CR_STARTBRK: It can only be set if STPBRK (Stop transmitter break) is not high This fixes tcsendbreak, which otherwise does not actually break. Signed-Off-By: Julien Malik <julien.malik@unseenlabs.fr> Link: https://lore.kernel.org/r/20230624210323.88455-1-julien.malik@unseenlabs.fr Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-18serial: xilinx_uartps: Use port lock wrappersThomas Gleixner
When a serial port is used for kernel console output, then all modifications to the UART registers which are done from other contexts, e.g. getty, termios, are interference points for the kernel console. So far this has been ignored and the printk output is based on the principle of hope. The rework of the console infrastructure which aims to support threaded and atomic consoles, requires to mark sections which modify the UART registers as unsafe. This allows the atomic write function to make informed decisions and eventually to restore operational state. It also allows to prevent the regular UART code from modifying UART registers while printk output is in progress. All modifications of UART registers are guarded by the UART port lock, which provides an obvious synchronization point with the console infrastructure. To avoid adding this functionality to all UART drivers, wrap the spin_[un]lock*() invocations for uart_port::lock into helper functions which just contain the spin_[un]lock*() invocations for now. In a subsequent step these helpers will gain the console synchronization mechanisms. Converted with coccinelle. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20230914183831.587273-75-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-04tty: serial: xilinx_uartps: Do not check for 0 return after calling ↵Ruan Jinjie
platform_get_irq() Since commit a85a6c86c25b ("driver core: platform: Clarify that IRQ 0 is invalid"), there is no possible for platform_get_irq() to return 0. Use the return value from platform_get_irq(). Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com> Link: https://lore.kernel.org/r/20230803091712.596987-1-ruanjinjie@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-13serial: Make uart_remove_one_port() return voidUwe Kleine-König
The return value is only ever used as a return value for remove callbacks of platform drivers. This return value is ignored by the driver core. (The only effect is an error message, but uart_remove_one_port() already emitted one in this case.) So the return value isn't used at all and uart_remove_one_port() can be changed to return void without any loss. Also this better matches the Linux device model as remove functions are not supposed to fail. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20230512173810.131447-3-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-16Merge tag 'tty-6.2-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver updates from Greg KH: "Here is the "big" set of tty/serial driver changes for 6.2-rc1. As in previous kernel releases, nothing big here at all, just some small incremental serial/tty layer cleanups and some individual driver additions and fixes. Highlights are: - serial helper macros from Jiri Slaby to reduce the amount of duplicated code in serial drivers - api cleanups and consolidations from Ilpo Järvinen in lots of serial drivers - the usual set of n_gsm fixes from Daniel Starke as that code gets exercised more - TIOCSTI is finally able to be disabled if requested (security hardening feature from Kees Cook) - fsl_lpuart driver fixes and features added - other small serial driver additions and fixes All of these have been in linux-next for a while with no reported problems" * tag 'tty-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (97 commits) serial: atmel: don't stop the transmitter when doing PIO serial: atmel: cleanup atmel_start+stop_tx() tty: serial: fsl_lpuart: switch to new dmaengine_terminate_* API serial: sunsab: Fix error handling in sunsab_init() serial: altera_uart: fix locking in polling mode serial: pch: Fix PCI device refcount leak in pch_request_dma() tty: serial: fsl_lpuart: Use pm_ptr() to avoid need to make pm __maybe_unused tty: serial: fsl_lpuart: Add runtime pm support tty: serial: fsl_lpuart: enable wakeup source for lpuart serdev: Replace poll loop by readx_poll_timeout() macro tty: synclink_gt: unwind actions in error path of net device open serial: stm32: move dma_request_chan() before clk_prepare_enable() dt-bindings: serial: xlnx,opb-uartlite: Drop 'contains' from 'xlnx,use-parity' serial: pl011: Do not clear RX FIFO & RX interrupt in unthrottle. serial: amba-pl011: avoid SBSA UART accessing DMACR register tty: serial: altera_jtaguart: remove struct altera_jtaguart tty: serial: altera_jtaguart: use uart_port::read_status_mask tty: serial: altera_jtaguart: remove unused altera_jtaguart::sigs tty: serial: altera_jtaguart: remove flag from altera_jtaguart_rx_chars() n_tty: Rename tail to old_tail in n_tty_read() ...
2022-12-02tty: serial: xilinx_uartps: use console_is_registered()John Ogness
It is not reliable to check for CON_ENABLED in order to identify if a console is registered. Use console_is_registered() instead. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-30-john.ogness@linutronix.de
2022-11-03serial: xuartps: Use uart_xmit_advance()Ilpo Järvinen
Take advantage of the new uart_xmit_advance() helper. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221019091151.6692-44-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-30serial: Make ->set_termios() old ktermios constIlpo Järvinen
There should be no reason to adjust old ktermios which is going to get discarded anyway. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220816115739.10928-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-30tty: xilinx_uartps: Check the clk_enable return valueShubhrajyoti Datta
Check the clk_enable return value. If clocks are not enabled the register accesses could hang the system so error out instead. Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Link: https://lore.kernel.org/r/20220729114748.18332-8-shubhrajyoti.datta@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-30tty: xilinx_uartps: Add timeout waiting for loopShubhrajyoti Datta
There is a potential infinite loop while waiting for the the TXFULL to deassert. Adds the error message and timeout to avoid infinite loop if it fails to get the TX fifo not full. Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Link: https://lore.kernel.org/r/20220729114748.18332-7-shubhrajyoti.datta@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-30tty: xilinx_uartps: Prevent writes when the controller is disabledShubhrajyoti Datta
Prevent writing to the fifo if the controller is disabled. Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Link: https://lore.kernel.org/r/20220729114748.18332-6-shubhrajyoti.datta@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-30tty: xilinx_uartps: Fix the ignore_statusShubhrajyoti Datta
Currently the ignore_status is not considered in the isr. Add a check to add the ignore_status. Fixes: 61ec9016988f ("tty/serial: add support for Xilinx PS UART") Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Link: https://lore.kernel.org/r/20220729114748.18332-5-shubhrajyoti.datta@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-30tty: xilinx_uartps: Initialise the read_status_maskShubhrajyoti Datta
Initialise the read status in probe. It will be checked in the isr so to have the default values lets initialise in probe. Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Link: https://lore.kernel.org/r/20220729114748.18332-4-shubhrajyoti.datta@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-30tty: xilinx_uartps: Update copyright text to correct formatMichal Simek
Based on recommended guidance Copyright term should be also present in front of (c). That's why aligned drivers to match this pattern. It helps automated tools with source code scanning. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Link: https://lore.kernel.org/r/20220729114748.18332-3-shubhrajyoti.datta@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-30tty: xilinx_uartps: Check clk_enable return valueShubhrajyoti Datta
If clocks are not enabled the register access may hang the system. Check for the clock enable return value and bail out if not enabled. Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Link: https://lore.kernel.org/r/20220729114748.18332-2-shubhrajyoti.datta@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: xilinx_uartps: cache xmit in cdns_uart_handle_tx()Jiri Slaby
Cache port->state->xmit into a local variable (xmit) in cdns_uart_handle_tx(). This reduces length of some lines there significantly. I.e. makes the code more readable. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220421101708.5640-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: xilinx_uartps: return early in cdns_uart_handle_tx()Jiri Slaby
Return from the true branch of the 'if'. This saves one indentation level and makes the code more readable. The two comments about what obvious code does are removed too. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220421101708.5640-3-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-03serial: make uart_console_write->putchar()'s character an unsigned charJiri Slaby
Currently, uart_console_write->putchar's second parameter (the character) is of type int. It makes little sense, provided uart_console_write() accepts the input string as "const char *s" and passes its content -- the characters -- to putchar(). So switch the character's type to unsigned char. We don't use char as that is signed on some platforms. That would cause troubles for drivers which (implicitly) cast the char to u16 when writing to the device. Sign extension would happen in that case and the value written would be completely different to the provided char. DZ is an example of such a driver -- on MIPS, it uses u16 for dz_out in dz_console_putchar(). Note we do the char -> uchar conversion implicitly in uart_console_write(). Provided we do not change size of the data type, sign extension does not happen there, so the problem is void. This makes the types consistent and unified with the rest of the uart layer, which uses unsigned char in most places already. One exception is xmit_buf, but that is going to be converted later. Cc: Paul Cercueil <paul@crapouillou.net> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Nicolas Ferre <nicolas.ferre@microchip.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Ludovic Desroches <ludovic.desroches@microchip.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: "Maciej W. Rozycki" <macro@orcam.me.uk> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Pengutronix Kernel Team <kernel@pengutronix.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: NXP Linux Team <linux-imx@nxp.com> Cc: Karol Gugala <kgugala@antmicro.com> Cc: Mateusz Holenko <mholenko@antmicro.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Neil Armstrong <narmstrong@baylibre.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Jerome Brunet <jbrunet@baylibre.com> Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Cc: Taichi Sugaya <sugaya.taichi@socionext.com> Cc: Takao Orito <orito.takao@socionext.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Manivannan Sadhasivam <mani@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Andy Gross <agross@kernel.org> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Cc: Orson Zhai <orsonzhai@gmail.com> Cc: Baolin Wang <baolin.wang7@gmail.com> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: Patrice Chotard <patrice.chotard@foss.st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Korsgaard <peter@korsgaard.com> Cc: Michal Simek <michal.simek@xilinx.com> Acked-by: Richard Genoud <richard.genoud@gmail.com> [atmel_serial] Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Paul Cercueil <paul@crapouillou.net> Acked-by: Neil Armstrong <narmstrong@baylibre.com> # meson_serial Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220303080831.21783-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-26serial: xilinx_uartps: Fix race condition causing stuck TXAnssi Hannula
xilinx_uartps .start_tx() clears TXEMPTY when enabling TXEMPTY to avoid any previous TXEVENT event asserting the UART interrupt. This clear operation is done immediately after filling the TX FIFO. However, if the bytes inserted by cdns_uart_handle_tx() are consumed by the UART before the TXEMPTY is cleared, the clear operation eats the new TXEMPTY event as well, causing cdns_uart_isr() to never receive the TXEMPTY event. If there are bytes still queued in circbuf, TX will get stuck as they will never get transferred to FIFO (unless new bytes are queued to circbuf in which case .start_tx() is called again). While the racy missed TXEMPTY occurs fairly often with short data sequences (e.g. write 1 byte), in those cases circbuf is usually empty so no action on TXEMPTY would have been needed anyway. On the other hand, longer data sequences make the race much more unlikely as UART takes longer to consume the TX FIFO. Therefore it is rare for this race to cause visible issues in general. Fix the race by clearing the TXEMPTY bit in ISR *before* filling the FIFO. The TXEMPTY bit in ISR will only get asserted at the exact moment the TX FIFO *becomes* empty, so clearing the bit before filling FIFO does not cause an extra immediate assertion even if the FIFO is initially empty. This is hard to reproduce directly on a normal system, but inserting e.g. udelay(200) after cdns_uart_handle_tx(port), setting 4000000 baud, and then running "dd if=/dev/zero bs=128 of=/dev/ttyPS0 count=50" reliably reproduces the issue on my ZynqMP test system unless this fix is applied. Fixes: 85baf542d54e ("tty: xuartps: support 64 byte FIFO size") Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi> Link: https://lore.kernel.org/r/20211026102741.2910441-1-anssi.hannula@bitwise.fi Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-24serial: Prefer unsigned int to bare use of unsignedJinchao Wang
Fix checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' Signed-off-by: Jinchao Wang <wjc@cdjrlc.com> Link: https://lore.kernel.org/r/20210624021207.58059-1-wjc@cdjrlc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-20tty: serial: xilinx_uartps: Fix documentation for cdns_uart_clk_notifier_cb()Lee Jones
Fixes the following W=1 kernel build warning(s): drivers/tty/serial/xilinx_uartps.c:496: warning: expecting prototype for cdns_uart_clk_notitifer_cb(). Prototype was for cdns_uart_clk_notifier_cb() instead Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Michal Simek <michal.simek@xilinx.com> Cc: linux-serial@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Reviewed-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Lee Jones <lee.jones@linaro.org> Link: https://lore.kernel.org/r/20210520121906.3468725-12-lee.jones@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-20serial: drop irq-flags initialisationsJohan Hovold
There's no need to initialise irq-flags variables before saving the interrupt state. Drop the redundant initialisations from drivers that got this wrong. Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210519092541.10137-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22serial: xilinx_uartps: drop low-latency workaroundJohan Hovold
Commit c8dbdc842d30 ("serial: xuartps: Rewrite the interrupt handling logic") reworked the driver interrupt processing but also, without comment, added an unnecessary workaround for the infamous low_latency behaviour of tty_flip_buffer_push() which had been removed years before. 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. Cc: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210421095509.3024-27-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-06tty: serial: xilinx_uartps: Supply description for missing member 'cts_override'Lee Jones
Fixes the following W=1 kernel build warning(s): drivers/tty/serial/xilinx_uartps.c:205: warning: Function parameter or member 'cts_override' not described in 'cdns_uart' Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Michal Simek <michal.simek@xilinx.com> Cc: linux-serial@vger.kernel.org Signed-off-by: Lee Jones <lee.jones@linaro.org> Link: https://lore.kernel.org/r/20201104193549.4026187-23-lee.jones@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-07-21tty: xilinx_uartps: Really fix id assignmentHelmut Grohne
The problems started with the revert (18cc7ac8a28e28). The cdns_uart_console.index is statically assigned -1. When the port is registered, Linux assigns consecutive numbers to it. It turned out that when using ttyPS1 as console, the index is not updated as we are reusing the same cdns_uart_console instance for multiple ports. When registering ttyPS0, it gets updated from -1 to 0, but when registering ttyPS1, it already is 0 and not updated. That led to 2ae11c46d5fdc4. It assigns the index prior to registering the uart_driver once. Unfortunately, that ended up breaking the situation where the probe order does not match the id order. When using the same device tree for both uboot and linux, it is important that the serial0 alias points to the console. So some boards reverse those aliases. This was reported by Jan Kiszka. The proposed fix was reverting the index assignment and going back to the previous iteration. However such a reversed assignement (serial0 -> uart1, serial1 -> uart0) was already partially broken by the revert (18cc7ac8a28e28). While the ttyPS device works, the kmsg connection is already broken and kernel messages go missing. Reverting the id assignment does not fix this. >From the xilinx_uartps driver pov (after reverting the refactoring commits), there can be only one console. This manifests in static variables console_pprt and cdns_uart_console. These variables are not properly linked and can go out of sync. The cdns_uart_console.index is important for uart_add_one_port. We call that function for each port - one of which hopefully is the console. If it isn't, the CON_ENABLED flag is not set and console_port is cleared. The next cdns_uart_probe call then tries to register the next port using that same cdns_uart_console. It is important that console_port and cdns_uart_console (and its index in particular) stay in sync. The index assignment implemented by Shubhrajyoti Datta is correct in principle. It just may have to happen a second time if the first cdns_uart_probe call didn't encounter the console device. And we shouldn't change the index once the console uart is registered. Reported-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Reported-by: Jan Kiszka <jan.kiszka@web.de> Link: https://lore.kernel.org/linux-serial/f4092727-d8f5-5f91-2c9f-76643aace993@siemens.com/ Fixes: 18cc7ac8a28e28 ("Revert "serial: uartps: Register own uart console and driver structures"") Fixes: 2ae11c46d5fdc4 ("tty: xilinx_uartps: Fix missing id assignment to the console") Fixes: 76ed2e10579671 ("Revert "tty: xilinx_uartps: Fix missing id assignment to the console"") Signed-off-by: Helmut Grohne <helmut.grohne@intenta.de> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200713073227.GA3805@laureti-dev Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-27Revert "tty: xilinx_uartps: Fix missing id assignment to the console"Jan Kiszka
This reverts commit 2ae11c46d5fdc46cb396e35911c713d271056d35. It turned out to break the ultra96-rev1, e.g., which uses uart1 as serial0 (and stdout-path = "serial0:115200n8"). Fixes: 2ae11c46d5fd ("tty: xilinx_uartps: Fix missing id assignment to the console") Cc: stable <stable@vger.kernel.org> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Reviewed-by: Michal Simek <michal.simek@xilinx.com> Tested-by: Michal Simek <michal.simek@xilinx.com> Link: https://lore.kernel.org/r/f4092727-d8f5-5f91-2c9f-76643aace993@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-11Merge 5.7-rc5 into tty-nextGreg Kroah-Hartman
We need the tty fixes in here too. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-04tty: xilinx_uartps: Fix missing id assignment to the consoleShubhrajyoti Datta
When serial console has been assigned to ttyPS1 (which is serial1 alias) console index is not updated property and pointing to index -1 (statically initialized) which ends up in situation where nothing has been printed on the port. The commit 18cc7ac8a28e ("Revert "serial: uartps: Register own uart console and driver structures"") didn't contain this line which was removed by accident. Fixes: 18cc7ac8a28e ("Revert "serial: uartps: Register own uart console and driver structures"") Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Link: https://lore.kernel.org/r/ed3111533ef5bd342ee5ec504812240b870f0853.1588602446.git.michal.simek@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-27Merge 5.7-rc3 into tty-nextGreg Kroah-Hartman
We need the tty/serial fixes in here too. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16serial: uartps: Use cdns_uart_tx_empty in console_writeRaviteja Narayanam
Instead of accessing the registers and checking for tx_empty, use cdns_uart_tx_empty in cdns_uart_console_write function. Signed-off-by: Raviteja Narayanam <raviteja.narayanam@xilinx.com> Reviewed-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Link: https://lore.kernel.org/r/1586413563-29125-3-git-send-email-raviteja.narayanam@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16serial: uartps: Wait for tx_empty in console setupRaviteja Narayanam
On some platforms, the log is corrupted while console is being registered. It is observed that when set_termios is called, there are still some bytes in the FIFO to be transmitted. So, wait for tx_empty inside cdns_uart_console_setup before calling set_termios. Signed-off-by: Raviteja Narayanam <raviteja.narayanam@xilinx.com> Reviewed-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Link: https://lore.kernel.org/r/1586413563-29125-2-git-send-email-raviteja.narayanam@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16Revert "serial: uartps: Register own uart console and driver structures"Michal Simek
This reverts commit 024ca329bfb9a948f76eaff3243e21b7e70182f2. As Johan says, this driver needs a lot more work and these changes are only going in the wrong direction: https://lkml.kernel.org/r/20190523091839.GC568@localhost Reported-by: Johan Hovold <johan@kernel.org> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/1ee35667e36a8efddee381df5fe495ad65f4d15c.1585905873.git.michal.simek@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16Revert "serial: uartps: Move Port ID to device data structure"Michal Simek
This reverts commit bed25ac0e2b6ab8f9aed2d20bc9c3a2037311800. As Johan says, this driver needs a lot more work and these changes are only going in the wrong direction: https://lkml.kernel.org/r/20190523091839.GC568@localhost Reported-by: Johan Hovold <johan@kernel.org> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/eb0ec98fecdca9b79c1a3ac0c30c668b6973b193.1585905873.git.michal.simek@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16Revert "serial: uartps: Change uart ID port allocation"Michal Simek
This reverts commit ae1cca3fa3478be92948dbbcd722390272032ade. With setting up NR_PORTS to 16 to be able to use serial2 and higher aliases and don't loose functionality which was intended by these changes. As Johan says, this driver needs a lot more work and these changes are only going in the wrong direction: https://lkml.kernel.org/r/20190523091839.GC568@localhost Reported-by: Johan Hovold <johan@kernel.org> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/a94931b65ce0089f76fb1fe6b446a08731bff754.1585905873.git.michal.simek@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16Revert "serial: uartps: Do not allow use aliases >= MAX_UART_INSTANCES"Michal Simek
This reverts commit 2088cfd882d0403609bdf426e9b24372fe1b8337. As Johan says, this driver needs a lot more work and these changes are only going in the wrong direction: https://lkml.kernel.org/r/20190523091839.GC568@localhost Reported-by: Johan Hovold <johan@kernel.org> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/dac3898e3e32d963f357fb436ac9a7ac3cbcf933.1585905873.git.michal.simek@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16Revert "serial: uartps: Fix error path when alloc failed"Michal Simek
This reverts commit 32cf21ac4edd6c0d5b9614368a83bcdc68acb031. As Johan says, this driver needs a lot more work and these changes are only going in the wrong direction: https://lkml.kernel.org/r/20190523091839.GC568@localhost Reported-by: Johan Hovold <johan@kernel.org> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/46cd7f039db847c08baa6508edd7854f7c8ff80f.1585905873.git.michal.simek@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16Revert "serial: uartps: Use the same dynamic major number for all ports"Michal Simek
This reverts commit ab262666018de6f4e206b021386b93ed0c164316. As Johan says, this driver needs a lot more work and these changes are only going in the wrong direction: https://lkml.kernel.org/r/20190523091839.GC568@localhost Reported-by: Johan Hovold <johan@kernel.org> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/14a565fc1e14a5ec6cc6a6710deb878ae8305f22.1585905873.git.michal.simek@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16Revert "serial: uartps: Fix uartps_major handling"Michal Simek
This reverts commit 5e9bd2d70ae7c00a95a22994abf1eef728649e64. As Johan says, this driver needs a lot more work and these changes are only going in the wrong direction: https://lkml.kernel.org/r/20190523091839.GC568@localhost Reported-by: Johan Hovold <johan@kernel.org> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/310999ab5342f788a7bc1b0e68294d4f052cad07.1585905873.git.michal.simek@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>