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2022-04-26serial: 8250: dw: Add support for DMA flow controlling devicesPhil Edworthy
DW based controllers like the one on Renesas RZ/N1 must be programmed as flow controllers when using DMA. * Table 11.45 of the system manual, "Flow Control Combinations", states that using UART with DMA requires setting the DMA in the peripheral flow controller mode regardless of the direction. * Chapter 11.6.1.3 of the system manual, "Basic Interface Definitions", explains that the burst size in the above case must be configured in the peripheral's register DEST/SRC_BURST_SIZE. Experiments shown that upon Rx timeout, the DMA transaction needed to be manually cleared as well. Co-developed-by: Miquel Raynal <miquel.raynal@bootlin.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20220422180615.9098-9-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: dw: Move the IO accessors to 8250_dwlib.hMiquel Raynal
These accessors should be used instead of the regular readl/writel() helpers. In order to use them also from 8250_dw.c in this directory, move the helpers to 8250_dwlib.h There is no functional change. There is no need for declaring `struct uart_port` or even UPIO_MEM32BE which both are already included in the 8250_dwlib.h header by 8250.h. Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20220422180615.9098-8-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: dw: Introduce an rx_timeout variable in the IRQ pathMiquel Raynal
In a next change we are going to need the same Rx timeout condition as we already have in the IRQ handling code. Let's just create a boolean to clarify what this operation does before reusing it. There is no functional change. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20220422180615.9098-7-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: dma: Allow driver operations before starting DMA transfersMiquel Raynal
One situation where this could be used is when configuring the UART controller to be the DMA flow controller. This is a typical case where the driver might need to program a few more registers before starting a DMA transfer. Provide the necessary infrastructure to support this case. Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20220422180615.9098-6-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: dw: Allow to use a fallback CPR value if not synthesizedMiquel Raynal
DW UART controllers can be synthesized without the CPR register. In this case, allow to the platform information to provide a CPR value. Co-developed-by: Phil Edworthy <phil.edworthy@renesas.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20220422180615.9098-5-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: dw: Move the USR register to pdataMiquel Raynal
This offset is a good candidate to pdata's because it changes depending on the vendor implementation. Let's move the usr_reg entry from regular to pdata. This way we can drop initializing it at run time. Let's also use a define for it instead of defining only the default value. Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20220422180615.9098-4-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: dw: Create a generic platform data structureEmil Renner Berthing
Use device tree match data rather than multiple calls to of_device_is_compatible() by introducing a platform data structure and adding a quirks mask. Provide a stub to the compatibles without quirks to simplify the handling of the upcoming changes. Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Emil Renner Berthing <kernel@esmil.dk> [<miquel.raynal@bootlin.com: Minor changes + creation of a real pdata structure] Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20220422180615.9098-3-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: dw: Move definitions to the shared headerPhil Edworthy
Move the per-device structure and a helper out of the main .c file, into a shared header as they will both be reused from another .c file. There is no functional change. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com> [miquel.raynal@bootlin.com: Extracted from a bigger change] Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20220422180615.9098-2-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26sysrq: do not omit current cpu when showing backtrace of all active CPUsChangbin Du
The backtrace of current CPU also should be printed as it is active. This change add stack trace for current CPU and print a hint for idle CPU for the generic workqueue based printing. (x86 already does this) Now it looks like below: [ 279.401567] sysrq: Show backtrace of all active CPUs [ 279.407234] sysrq: CPU5: [ 279.407505] Call Trace: [ 279.408789] [<ffffffff8000606c>] dump_backtrace+0x2c/0x3a [ 279.411698] [<ffffffff800060ac>] show_stack+0x32/0x3e [ 279.411809] [<ffffffff80542258>] sysrq_handle_showallcpus+0x4c/0xc6 [ 279.411929] [<ffffffff80542f16>] __handle_sysrq+0x106/0x26c [ 279.412034] [<ffffffff805436a8>] write_sysrq_trigger+0x64/0x74 [ 279.412139] [<ffffffff8029cd48>] proc_reg_write+0x8e/0xe2 [ 279.412252] [<ffffffff8021a8f8>] vfs_write+0x90/0x2be [ 279.412362] [<ffffffff8021acd2>] ksys_write+0xa6/0xce [ 279.412467] [<ffffffff8021ad24>] sys_write+0x2a/0x38 [ 279.412689] [<ffffffff80003ff8>] ret_from_syscall+0x0/0x2 [ 279.417173] sysrq: CPU6: backtrace skipped as idling [ 279.417185] sysrq: CPU4: backtrace skipped as idling [ 279.417187] sysrq: CPU0: backtrace skipped as idling [ 279.417181] sysrq: CPU7: backtrace skipped as idling [ 279.417190] sysrq: CPU1: backtrace skipped as idling [ 279.417193] sysrq: CPU3: backtrace skipped as idling [ 279.417219] sysrq: CPU2: [ 279.419179] Call Trace: [ 279.419440] [<ffffffff8000606c>] dump_backtrace+0x2c/0x3a [ 279.419782] [<ffffffff800060ac>] show_stack+0x32/0x3e [ 279.420015] [<ffffffff80542b30>] showacpu+0x5c/0x96 [ 279.420317] [<ffffffff800ba71c>] flush_smp_call_function_queue+0xd6/0x218 [ 279.420569] [<ffffffff800bb438>] generic_smp_call_function_single_interrupt+0x14/0x1c [ 279.420798] [<ffffffff800079ae>] handle_IPI+0xaa/0x13a [ 279.421024] [<ffffffff804dcb92>] riscv_intc_irq+0x56/0x70 [ 279.421274] [<ffffffff80a05b70>] generic_handle_arch_irq+0x6a/0xfa [ 279.421518] [<ffffffff80004006>] ret_from_exception+0x0/0x10 [ 279.421750] [<ffffffff80096492>] rcu_idle_enter+0x16/0x1e Signed-off-by: Changbin Du <changbin.du@gmail.com> Link: https://lore.kernel.org/r/20220117154300.2808-1-changbin.du@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26tty: hvcs: simplify if-if to if-elseWan Jiabing
Use if and else instead of if(A) and if (!A) and fix a coding style. Signed-off-by: Wan Jiabing <wanjiabing@vivo.com> Link: https://lore.kernel.org/r/20220424091310.98780-1-wanjiabing@vivo.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26tty/hvc_opal: simplify if-if to if-elseWan Jiabing
Use if and else instead of if(A) and if (!A). Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Wan Jiabing <wanjiabing@vivo.com> Link: https://lore.kernel.org/r/20220426071041.168282-1-wanjiabing@vivo.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26tty: n_gsm: fix sometimes uninitialized warning in gsm_dlci_modem_output()Daniel Starke
'size' may be used uninitialized in gsm_dlci_modem_output() if called with an adaption that is neither 1 nor 2. The function is currently only called by gsm_modem_upd_via_data() and only for adaption 2. Properly handle every invalid case by returning -EINVAL to silence the compiler warning and avoid future regressions. Fixes: c19ffe00fed6 ("tty: n_gsm: fix invalid use of MSC in advanced option") Cc: stable@vger.kernel.org Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220425104726.7986-1-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22printk: add functions to prefer direct printingJohn Ogness
Once kthread printing is available, console printing will no longer occur in the context of the printk caller. However, there are some special contexts where it is desirable for the printk caller to directly print out kernel messages. Using pr_flush() to wait for threaded printers is only possible if the caller is in a sleepable context and the kthreads are active. That is not always the case. Introduce printk_prefer_direct_enter() and printk_prefer_direct_exit() functions to explicitly (and globally) activate/deactivate preferred direct console printing. The term "direct console printing" refers to printing to all enabled consoles from the context of the printk caller. The term "prefer" is used because this type of printing is only best effort. If the console is currently locked or other printers are already actively printing, the printk caller will need to rely on the other contexts to handle the printing. This preferred direct printing is how all printing has been handled until now (unless it was explicitly deferred). When kthread printing is introduced, there may be some unanticipated problems due to kthreads being unable to flush important messages. In order to minimize such risks, preferred direct printing is activated for the primary important messages when the system experiences general types of major errors. These are: - emergency reboot/shutdown - cpu and rcu stalls - hard and soft lockups - hung tasks - warn - sysrq Note that since kthread printing does not yet exist, no behavior changes result from this commit. This is only implementing the counter and marking the various places where preferred direct printing is active. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> # for RCU Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220421212250.565456-13-john.ogness@linutronix.de
2022-04-22serial: 8250: Correct the clock for EndRun PTP/1588 PCIe deviceMaciej W. Rozycki
The EndRun PTP/1588 dual serial port device is based on the Oxford Semiconductor OXPCIe952 UART device with the PCI vendor:device ID set for EndRun Technologies and is therefore driven by a fixed 62.5MHz clock input derived from the 100MHz PCI Express clock. The clock rate is divided by the oversampling rate of 16 as it is supplied to the baud rate generator, yielding the baud base of 3906250. Replace the incorrect baud base of 4000000 with the right value of 3906250 then, complementing commit 6cbe45d8ac93 ("serial: 8250: Correct the clock for OxSemi PCIe devices"). Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Cc: stable <stable@kernel.org> Fixes: 1bc8cde46a159 ("8250_pci: Added driver for Endrun Technologies PTP PCIe card.") Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181515270.9383@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: 8250: Also set sticky MCR bits in console restorationMaciej W. Rozycki
Sticky MCR bits are lost in console restoration if console suspending has been disabled. This currently affects the AFE bit, which works in combination with RTS which we set, so we want to make sure the UART retains control of its FIFO where previously requested. Also specific drivers may need other bits in the future. Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Fixes: 4516d50aabed ("serial: 8250: Use canary to restart console after suspend") Cc: stable@vger.kernel.org # v4.0+ Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181518490.9383@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22tty: n_gsm: fix software flow control handlingDaniel Starke
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010. See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516 The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to the newer 27.010 here. Chapter 5.4.8.1 states that XON/XOFF characters shall be used instead of Fcon/Fcoff command in advanced option mode to handle flow control. Chapter 5.4.8.2 describes how XON/XOFF characters shall be handled. Basic option mode only used Fcon/Fcoff commands and no XON/XOFF characters. These are treated as data bytes here. The current implementation uses the gsm_mux field 'constipated' to handle flow control from the remote peer and the gsm_dlci field 'constipated' to handle flow control from each DLCI. The later is unrelated to this patch. The gsm_mux field is correctly set for Fcon/Fcoff commands in gsm_control_message(). However, the same is not true for XON/XOFF characters in gsm1_receive(). Disable software flow control handling in the tty to allow explicit handling by n_gsm. Add the missing handling in advanced option mode for gsm_mux in gsm1_receive() to comply with the standard. This patch depends on the following commit: Commit 8838b2af23ca ("tty: n_gsm: fix SW flow control encoding/handling") Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220422071025.5490-3-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22tty: n_gsm: fix invalid use of MSC in advanced optionDaniel Starke
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010. See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516 The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to the newer 27.010 here. Chapter 5.4.6.3.7 states that the Modem Status Command (MSC) shall only be used if the basic option was chosen. The current implementation uses MSC frames even if advanced option was chosen to inform the peer about modem line state updates. A standard conform peer may choose to discard these frames in advanced option mode. Furthermore, gsmtty_modem_update() is not part of the 'tty_operations' functions despite its name. Rename gsmtty_modem_update() to gsm_modem_update() to clarify this. Split its function into gsm_modem_upd_via_data() and gsm_modem_upd_via_msc() depending on the encoding and adaption. Introduce gsm_dlci_modem_output() as adaption of gsm_dlci_data_output() to encode and queue empty frames in advanced option mode. Use it in gsm_modem_upd_via_data(). gsm_modem_upd_via_msc() is based on the initial gsmtty_modem_update() function which used only MSC frames to update modem states. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220422071025.5490-2-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22tty: n_gsm: fix broken virtual tty handlingDaniel Starke
Dynamic virtual tty registration was introduced to allow the user to handle these cases with uevent rules. The following commits relate to this: Commit 5b87686e3203 ("tty: n_gsm: Modify gsmtty driver register method when config requester") Commit 0b91b5332368 ("tty: n_gsm: Save dlci address open status when config requester") Commit 46292622ad73 ("tty: n_gsm: clean up indenting in gsm_queue()") However, the following behavior can be seen with this implementation: - n_gsm ldisc is activated via ioctl - all configuration parameters are set to their default value (initiator=0) - the mux gets activated and attached and gsmtty0 is being registered in in gsm_dlci_open() after DLCI 0 was established (DLCI 0 is the control channel) - the user configures n_gsm via ioctl GSMIOC_SETCONF as initiator - this re-attaches the n_gsm mux - no new gsmtty devices are registered in gsmld_attach_gsm() because the mux is already active - the initiator side registered only the control channel as gsmtty0 (which should never happen) and no user channel tty The commits above make it impossible to operate the initiator side as no user channel tty is or will be available. On the other hand, this behavior will make it also impossible to allow DLCI parameter negotiation on responder side in the future. The responder side first needs to provide a device for the application before the application can set its parameters of the associated DLCI via ioctl. Note that the user application is still able to detect a link establishment without relaying to uevent by waiting for DTR open on responder side. This is the same behavior as on a physical serial interface. And on initiator side a tty hangup can be detected if a link establishment request failed. Revert the commits above completely to always register all user channels and no control channel after mux attachment. No other changes are made. Fixes: 5b87686e3203 ("tty: n_gsm: Modify gsmtty driver register method when config requester") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220422071025.5490-1-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22Revert "serial: sc16is7xx: Clear RS485 bits in the shutdown"Hui Wang
This reverts commit 927728a34f11b5a27f4610bdb7068317d6fdc72a. Once the uart_port->rs485->flag is set to SER_RS485_ENABLED, the port should always work in RS485 mode. If users want the port to leave RS485 mode, they need to call ioctl() to clear SER_RS485_ENABLED. So here we shouldn't clear the RS485 bits in the shutdown(). Fixes: 927728a34f11 ("serial: sc16is7xx: Clear RS485 bits in the shutdown") Signed-off-by: Hui Wang <hui.wang@canonical.com> Link: https://lore.kernel.org/r/20220418094339.678144-1-hui.wang@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: stm32: add earlycon supportValentin Caron
Add early console support in stm32 uart driver. Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20220419085330.1178925-4-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: stm32: add KGDB supportValentin Caron
Add support for KGDB in stm32 serial driver by implementing characters polling callbacks (poll_init, poll_get_char and poll_put_char). Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Signed-off-by: Jean Philippe Romain <jean-philippe.romain@foss.st.com> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20220419085330.1178925-3-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: stm32: remove infinite loop possibility in putchar functionValentin Caron
Rework stm32_usart_console_putchar() function in order to anticipate the case where the character can never be sent. Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20220419085330.1178925-2-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22tty: Add function for handling flow control charsIlpo Järvinen
Move receive path flow control character handling to own function. No functional changes. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220411094859.10894-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: core: fix tcdrain() with CTS enabledTomasz Moń
Do not set timeout to twice the approximate amount of time to send the entire FIFO if CTS is enabled. If the caller requested no timeout, e.g. when userspace program called tcdrain(), then wait without any timeout. Premature return from tcdrain() was observed on imx based system which has 32 character long transmitter FIFO with hardware CTS handling. Simple userspace application that reproduces problem has to: * Open tty device, enable hardware flow control (CRTSCTS) * Write data, e.g. 26 bytes * Call tcdrain() to wait for the transmitter * Close tty device The other side of serial connection has to: * Receive some data, e.g. 10 bytes * Set RTS output (CTS input from sender perspective) inactive for at least twice the port timeout * Try to receive remaining data Without this patch, userspace application will finish without any error while the other side of connection will never receive remaining data. Signed-off-by: Tomasz Moń <tomasz.mon@camlingroup.com> Link: https://lore.kernel.org/r/20220228054911.1420221-1-tomasz.mon@camlingroup.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial/8250: Use fifo in 8250 console driverWander Lairson Costa
Note: I am using a small test app + driver located at [0] for the problem description. serco is a driver whose write function dispatches to the serial controller. sertest is a user-mode app that writes n bytes to the serial console using the serco driver. While investigating a bug in the RHEL kernel, I noticed that the serial console throughput is way below the configured speed of 115200 bps in a HP Proliant DL380 Gen9. I was expecting something above 10KB/s, but I got 2.5KB/s. $ time ./sertest -n 2500 /tmp/serco real 0m0.997s user 0m0.000s sys 0m0.997s With the help of the function tracer, I then noticed the serial controller was taking around 410us seconds to dispatch one single byte: $ trace-cmd record -p function_graph -g serial8250_console_write \ ./sertest -n 1 /tmp/serco $ trace-cmd report | serial8250_console_write() { 0.384 us | _raw_spin_lock_irqsave(); 1.836 us | io_serial_in(); 1.667 us | io_serial_out(); | uart_console_write() { | serial8250_console_putchar() { | wait_for_xmitr() { 1.870 us | io_serial_in(); 2.238 us | } 1.737 us | io_serial_out(); 4.318 us | } 4.675 us | } | wait_for_xmitr() { 1.635 us | io_serial_in(); | __const_udelay() { 1.125 us | delay_tsc(); 1.429 us | } ... ... ... 1.683 us | io_serial_in(); | __const_udelay() { 1.248 us | delay_tsc(); 1.486 us | } 1.671 us | io_serial_in(); 411.342 us | } In another machine, I measured a throughput of 11.5KB/s, with the serial controller taking between 80-90us to send each byte. That matches the expected throughput for a configuration of 115200 bps. This patch changes the serial8250_console_write to use the 16550 fifo if available. In my benchmarks I got around 25% improvement in the slow machine, and no performance penalty in the fast machine. Signed-off-by: Wander Lairson Costa <wander@redhat.com> Link: https://lore.kernel.org/r/20220411174841.34936-2-wander@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22drivers: tty: serial: Fix deadlock in sa1100_set_termios()Duoming Zhou
There is a deadlock in sa1100_set_termios(), which is shown below: (Thread 1) | (Thread 2) | sa1100_enable_ms() sa1100_set_termios() | mod_timer() spin_lock_irqsave() //(1) | (wait a time) ... | sa1100_timeout() del_timer_sync() | spin_lock_irqsave() //(2) (wait timer to stop) | ... We hold sport->port.lock in position (1) of thread 1 and use del_timer_sync() to wait timer to stop, but timer handler also need sport->port.lock in position (2) of thread 2. As a result, sa1100_set_termios() will block forever. This patch moves del_timer_sync() before spin_lock_irqsave() in order to prevent the deadlock. Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Link: https://lore.kernel.org/r/20220417111626.7802-1-duoming@zju.edu.cn Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22tty/sysrq: change the definition of sysrq_key_table's element to make it ↵Junwen Wu
more readable The definition of sysrq_key_table's elements, like sysrq_thaw_op and sysrq_showallcpus_op are not consistent with sysrq_ftrace_dump_op, Consistency makes code more readable. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Junwen Wu <wudaemon@gmail.com> Link: https://lore.kernel.org/r/20220418153703.97705-1-wudaemon@163.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22tty: serial: fsl_lpuart: remove the count initialization as it is not neededSherry Sun
No need to initialize the count variable in lpuart_copy_rx_to_tty(), so let's remove it here. Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20220418021844.29591-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: allow COMPILE_TEST for some driversJiri Slaby
Some more serial drivers can be compile-tested under certain circumstances (when building a specific architecture). So allow for that. This reduces the need of zillion mach/subarch-specific configs. And since the 0day bot has only allmodconfig's for some archs, this increases build coverage there too. Note that cpm needs a minor update in the header, so that it drags in at least some defines (CPM2 ones). Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220421101708.5640-8-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: pic32: make SERIAL_PIC32_CONSOLE depend on SERIAL_PIC32=yJiri Slaby
pic32_uart contains this: #ifdef CONFIG_SERIAL_PIC32_CONSOLE ... console_initcall(pic32_console_init); ... core_initcall(pic32_late_console_init); ... #endif ... arch_initcall(pic32_uart_init); When the driver is built as module, all three above become module_init(). So if SERIAL_PIC32_CONSOLE is set while SERIAL_PIC32=m, it results in the following build error: In file included from include/linux/device/driver.h:21, from include/linux/device.h:32, from include/linux/platform_device.h:13, from drivers/tty/serial/pic32_uart.c:12: include/linux/module.h:131:49: error: redefinition of '__inittest' So make sure SERIAL_PIC32_CONSOLE can be set only when SERIAL_PIC32=y -- similar as for other drivers. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220421101708.5640-7-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: qcom: use check for empty instead of pendingJiri Slaby
The code wants to know if the circ buffer is empty, so use the proper macro. No functional change intended, just saner function name used for that use case. Cc: Andy Gross <agross@kernel.org> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220421101708.5640-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: zs: use NULL as a pointer, not 0Jiri Slaby
struct uart_port::membase is declared as a pointer. So it should be initialized by NULL, not zero constant. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220421101708.5640-5-jslaby@suse.cz 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>
2022-04-22serial: sunplus-uart: change sunplus_console_ports from global to staticTom Rix
Smatch reports this issue sunplus-uart.c:501:26: warning: symbol 'sunplus_console_ports' was not declared. Should it be static? sunplus_console_ports is only used in sunplus-uart.c so change its storage-class specifier to static Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Tom Rix <trix@redhat.com> Link: https://lore.kernel.org/r/20220421152505.1531507-1-trix@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22tty: serial: meson: Added S4 SOC compatibilityYu Tu
Make UART driver compatible with S4 SOC UART. Meanwhile, the S4 SOC UART uses 12MHz as the clock source for baud rate calculations. Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Yu Tu <yu.tu@amlogic.com> Link: https://lore.kernel.org/r/20220422111320.19234-3-yu.tu@amlogic.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22tty: serial: meson: Add a 12MHz internal clock rate to calculate baud rate ↵Yu Tu
in order to meet the baud rate requirements of special BT modules A /2 divider over XTAL was introduced since G12A, and is preferred to be used over the still present /3 divider since it provides much closer frequencies vs the request baudrate. Especially the BT module uses 3Mhz baud rate. 8Mhz calculations can lead to baud rate bias, causing some problems. Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Yu Tu <yu.tu@amlogic.com> Link: https://lore.kernel.org/r/20220422111320.19234-2-yu.tu@amlogic.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: icom: remove unused struct icom_port membersJiri Slaby
Some members of struct icom_port are completely unused or only set and never read. Remove all those. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220421085808.24152-11-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: icom: delete empty serial hooksJiri Slaby
uart_ops::release_port() and uart_ops::request_port() are not required by the serial layer. So no need to define empty ones. Remove them. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220421085808.24152-10-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: icom: use list_for_each_entry()Jiri Slaby
Use list_for_each_entry() helper instead of explicit combo of list_for_each() and list_entry(). Note that pos is used as a reference point in list_add_tail() in icom_alloc_adapter(). This functionality remains as with an empty list, cur_adapter_entry->icom_adapter_entry is still the list head. This simplifies the code a bit. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220421085808.24152-9-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: icom: make icom_acfg_baud const and unsignedJiri Slaby
The baud rates are unsigned constants. So mark them as such. Not only it makes sense, but they are passed also to uart_get_baud_rate() and that expects unsigned int as baud rates on input. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220421085808.24152-8-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: icom: use ARRAY_SIZEJiri Slaby
Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220421085808.24152-7-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: icom: move header content to .cJiri Slaby
There is no point keeping the header content separated. The header was not even protected against double inclusion. So move the content to the appropriate source file. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220421085808.24152-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: icom: use proper __le types and functionsJiri Slaby
There is a lot of sparse warnings: .../icom.c:228:30: warning: cast from restricted __le16 .../icom.c:232:66: warning: incorrect type in assignment (different base types) .../icom.c:232:66: expected unsigned int [usertype] leBuffer .../icom.c:232:66: got restricted __le32 [usertype] .../icom.c:237:30: warning: cast from restricted __le16 ... .../icom.c:1228:22: warning: cast from restricted __le16 And they are correct. So sort them all out by using proper __leXX and uXX types and the right direction of conversion: le16_to_cpu() instead of cpu_to_le16(), where appropriate. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220421085808.24152-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: icom: remove to_icom_adapter() and icom_kref_release()Jiri Slaby
Integrate both the to_icom_adapter() macro and icom_kref_release() wrapper into icom_remove_adapter(). (And keep it icom_kref_release() name.) It makes the code easier to follow without complex indirections. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220421085808.24152-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: icom: switch vague casts to container_ofJiri Slaby
In icom, there is an ICOM_PORT macro to perform upcasts from struct uart_port to struct icom_port. It's not completely safe and it works only because the first member of icom_port is uart_port. Nowadays, we use container_of for such an upcast instead. So introduce a helper (to_icom_port()) with container_of in it and convert all the ICOM_PORT users to the new helper. Apart from the code and type safety, it's also clear what icom_port (the variable) is. Unlike with the old ICOM_PORT (the macro with the cast). Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220421085808.24152-3-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22serial: icom: remove ICOM_VERSION_STR macroJiri Slaby
It's unused, so remove the macro. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220421085808.24152-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-21serial: 8250/omap1: include linux/soc/ti/omap1-soc.hArnd Bergmann
As a preparation for cleaning up the omap1 headers, start including linux/soc/ti/omap1-soc.h directly so we can keep calling cpu_is_omap1510(). Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2022-04-20tty: n_gsm: clean up implicit CR bit encoding in address fieldDaniel Starke
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010. See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516 The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to the newer 27.010 here. Chapter 5.2.1.2 describes the encoding of the address field within the frame header. It is made up of the DLCI address, command/response (CR) bit and EA bit. Use the predefined CR value instead of a plain 2 in alignment to the remaining code and to make the encoding obvious. Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220420101346.3315-3-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-20tty: n_gsm: clean up dead code in gsm_queue()Daniel Starke
Remove commented out code as it is never used and if anyone accidentally turned it on, it would be broken. Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220420101346.3315-2-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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