- Mar 10, 2021
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Erwan Le Ray authored
Add the support for "flush_buffer" ops in order to flush any write buffers, reset any DMA state and stop any ongoing DMA transfers when the port->state->xmit circular buffer is cleared. Signed-off-by:
Erwan Le Ray <erwan.leray@foss.st.com> Link: https://lore.kernel.org/r/20210304162308.8984-14-erwan.leray@foss.st.com Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Erwan Le Ray authored
In "tx_empty", we should poll TC bit in both DMA and PIO modes (instead of TXE) to check transmission data register has been transmitted independently of the FIFO mode. TC indicates that both transmit register and shift register are empty. When shift register is empty, tx_empty should return TIOCSER_TEMT instead of TC value. Cleans the USART_CR_TC TCCF register define (transmission complete clear flag) as it is duplicate of USART_ICR_TCCF. Fixes: 48a6092f ("serial: stm32-usart: Add STM32 USART Driver") Signed-off-by:
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Erwan Le Ray authored
Transmission complete error is sent when ISR_TC is not set. If port closure is requested despite data in TDR / TX FIFO has not been sent (because of flow control), ISR_TC is not set and error message is sent on port closure but also when a new port is opened. Flush the data when port is closed, so the error isn't printed twice upon next port opening. Fixes: 64c32eab ("serial: stm32: Add support of TC bit status check") Signed-off-by:
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Erwan Le Ray authored
Fifo flush set USART_RQR register by calling stm32_usart_set_bits routine (Read/Modify/Write). USART_RQR register is a write only register. So, read before write isn't correct / relevant to flush the FIFOs. Replace stm32_usart_set_bits call by writel_relaxed. Fixes: 84872dc4 ("serial: stm32: add RX and TX FIFO flush") Signed-off-by:
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Erwan Le Ray authored
stm32_transmit_chars should be called under lock also in tx DMA callback. Fixes: 34891872 ("serial: stm32: adding dma support") Signed-off-by:
Fabrice Gasnier <fabrice.gasnier@foss.st.com> Link: https://lore.kernel.org/r/20210304162308.8984-10-erwan.leray@foss.st.com Signed-off-by:
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Erwan Le Ray authored
This patch add a proper release of dma channels when completing dma tx. Fixes: 34891872 ("serial: stm32: adding dma support") Signed-off-by:
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Erwan Le Ray authored
CTS/RTS GPIOs support that has been added recently to STM32 UART driver has introduced scheduled code in a set_termios part protected by a spin lock. This generates a potential deadlock scenario: Chain exists of: &irq_desc_lock_class --> console_owner --> &port_lock_key Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&port_lock_key); lock(console_owner); lock(&port_lock_key); lock(&irq_desc_lock_class); *** DEADLOCK *** 4 locks held by stty/766: Move the scheduled code after the spinlock. Fixes: 6cf61b9b ("tty: serial: Add modem control gpio support for STM32 UART") Signed-off-by: -
Erwan Le Ray authored
This patch fixes several issue with wake-up handling: - the WUF irq is handled several times at wake-up - the USART is disabled / enabled at suspend to set wake-up flag. It can cause glitches during RX. This patch fix those issues: - clear wake-up flag and disable wake-up irq in WUF irq handling - enable wake-up from low power on start bit detection at port configuration - Unmask the wake-up flag irq at suspend and mask it at resume In addition, pm_wakeup_event handling is moved from receice_chars to WUF irq handling. Fixes: 270e5a74 ("serial: stm32: add wakeup mechanism") Signed-off-by:
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Erwan Le Ray authored
Deadlock issue is seen when enabling CONFIG_PROVE_LOCKING=Y, and uart console as wakeup source. Deadlock occurs when resuming from low power mode if system is waked up via usart console. The deadlock is triggered 100% when also disabling console suspend prior to go to suspend. Simplified call stack, deadlock condition: - stm32_console_write <-- spin_lock already held - print_circular_bug - pm_wakeup_dev_event <-- triggers lockdep as seen above - stm32_receive_chars - stm32_interrupt <-- wakeup via uart console, takes the lock So, revisit spin_lock in stm32-usart driver: - there is no need to hold the lock to access ICR (atomic clear of status flags) - only hold the lock inside stm32_receive_chars() routine (no need to call pm_wakeup_dev_event with lock held) - keep stm32_transmit_chars() routine called with lock held Fixes: 48a6092f ("serial: stm32-usart: Add STM32 USART Driver") Signed-off-by:
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Erwan Le Ray authored
TX and RX FIFO thresholds may be cleared after suspend/resume, depending on the low power mode. Those configurations (done in startup) are not effective for UART console, as: - the reference manual indicates that FIFOEN bit can only be written when the USART is disabled (UE=0) - a set_termios (where UE is set) is requested firstly for console enabling, before the startup. Fixes: 84872dc4 ("serial: stm32: add RX and TX FIFO flush") Signed-off-by:
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Erwan Le Ray authored
Incorrect characters are observed on console during boot. This issue occurs when init/main.c is modifying termios settings to open /dev/console on the rootfs. This patch adds a waiting loop in set_termios to wait for TX shift register empty (and TX FIFO if any) before stopping serial port. Fixes: 48a6092f ("serial: stm32-usart: Add STM32 USART Driver") Signed-off-by:
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Erwan Le Ray authored
RX is configured, but usart is not enabled in startup function. Kernel documentation specifies that startup should enable the port for reception. Fix the startup by enabling usart for reception. Fixes: 84872dc4 ("serial: stm32: add RX and TX FIFO flush") Signed-off-by:
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Erwan Le Ray authored
The probe and remove orders are wrong as the uart_port is registered before saving device data in the probe, and unregistered after DMA resource deallocation in the remove. uart_port registering should be done at the end of probe and unregistering should be done at the begin of remove to avoid resource allocation issues. Fix probe and remove orders. This enforce resource allocation occur at proper time. Terminate both DMA rx and tx transfers before removing device. Move pm_runtime after uart_remove_one_port() call in remove() to keep the probe error path. Fixes: 34891872 ("serial: stm32: adding dma support") Signed-off-by:
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Krzysztof Kozlowski authored
The Samsung SoC UART nodes have usually DMA so dtschema has to reflect this to fix dtbs_check warnings like: arch/arm/boot/dts/exynos4210-smdkv310.dt.yaml: serial@13800000: 'dma-names', 'dmas' do not match any of the regexes: 'pinctrl-[0-9]+' Signed-off-by:Krzysztof Kozlowski <krzk@kernel.org> Reviewed-by:
Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20210212163905.70171-1-krzk@kernel.org Signed-off-by:
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Wei Yongjun authored
In case of error, the function devm_platform_get_and_ioremap_resource() returns ERR_PTR() and never returns NULL. The NULL test in the return value check should be replaced with IS_ERR(). Fixes: 1da81e55 ("drivers/tty/serial: add LiteUART driver") Reported-by:
Hulk Robot <hulkci@huawei.com> Signed-off-by:
Wei Yongjun <weiyongjun1@huawei.com> Link: https://lore.kernel.org/r/20210305034929.3234352-1-weiyongjun1@huawei.com Signed-off-by:
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Heikki Krogerus authored
Software node is always created for additional device properties. If the properties are constant, the software node can also be constant. Reviewed-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by:
Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20210304081311.17340-1-heikki.krogerus@linux.intel.com Signed-off-by:
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Hector Martin authored
Earlycon support is identical to S3C2410, but Apple SoCs also need MMIO mapped as nGnRnE. This is handled generically for normal drivers including the normal UART path here, but earlycon uses fixmap and runs before that scaffolding is ready. Since this is the only case where we need this fix, it makes more sense to do it here in the UART driver instead of introducing a whole fdt nonposted-mmio resolver just for earlycon/fixmap. Suggested-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
Hector Martin <marcan@marcan.st> Reviewed-by:
Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Link: https://lore.kernel.org/r/20210304213902.83903-26-marcan@marcan.st Signed-off-by:
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Hector Martin authored
Apple SoCs are a distant descendant of Samsung designs and use yet another variant of their UART style, with different interrupt handling. In particular, this variant has the following differences with existing ones: * It includes a built-in interrupt controller with different registers, using only a single platform IRQ * Internal interrupt sources are treated as edge-triggered, even though the IRQ output is level-triggered. This chiefly affects the TX IRQ path: the driver can no longer rely on the TX buffer empty IRQ immediately firing after TX is enabled, but instead must prime the FIFO with data directly. Signed-off-by:
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Hector Martin authored
Apple mobile devices originally used Samsung SoCs (starting with the S5L8900), and their current in-house SoCs continue to use compatible UART peripherals. We'll call this UART variant apple,s5l-uart. Signed-off-by:
Linus Walleij <linus.walleij@linaro.org> Reviewed-by:
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Hector Martin authored
This picks up the non-posted I/O mode needed for Apple platforms to work properly. This removes the request/release functions, which are no longer necessary, since devm_ioremap_resource takes care of that already. Most other drivers already do it this way, anyway. Signed-off-by:
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Hector Martin authored
* Split out s3c24xx_serial_tx_chars from s3c24xx_serial_tx_irq, where only the latter acquires the port lock. This will be necessary on platforms which have edge-triggered IRQs, as we need to call s3c24xx_serial_tx_chars to kick off transmission from outside IRQ context, with the port lock held. * Rename s3c24xx_serial_rx_chars to s3c24xx_serial_rx_irq for consistency with the above. All it does now is call two other functions anyway. Signed-off-by:
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Hector Martin authored
This decouples the TTY layer PORT_ types, which are exposed to userspace, from the driver-internal flag of what kind of port this is. This removes s3c24xx_serial_has_interrupt_mask, which was just checking for a specific type anyway. Signed-off-by:
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Hector Martin authored
Instead of patching a single global ops structure depending on the port type, use a separate s3c64xx_serial_ops for the S3C64XX type. This allows us to mark the structures as const. Also split out s3c64xx_serial_shutdown into a separate function now that we have a separate ops structure; this avoids excessive branching control flow and mirrors s3c64xx_serial_startup. tx_claimed and rx_claimed are only used in the S3C24XX functions. Signed-off-by:
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Hector Martin authored
This simplifies the code by removing the only distinction between the S3C2410 and S3C2440 codepaths. Signed-off-by:
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Julian Braha authored
When SERIAL_IMX_EARLYCON is enabled, and SERIAL_CORE is disabled, Kbuild gives the following warning: WARNING: unmet direct dependencies detected for SERIAL_EARLYCON Depends on [n]: TTY [=y] && HAS_IOMEM [=y] && SERIAL_CORE [=n] Selected by [y]: - SERIAL_IMX_EARLYCON [=y] && TTY [=y] && HAS_IOMEM [=y] && (ARCH_MXC [=y] || COMPILE_TEST [=n]) && OF [=y] This is because SERIAL_IMX_EARLYCON selects SERIAL_EARLYCON, without selecting SERIAL_CORE, despite that config option depending on SERIAL_CORE. Signed-off-by:
Julian Braha <julianbraha@gmail.com> Link: https://lore.kernel.org/r/20210225044248.4745-1-julianbraha@gmail.com Signed-off-by:
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Jiri Slaby authored
The tty line disciplines don't expect tty_operations::write_room to return negative values. Fix the five drivers which violate this. Signed-off-by:
Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210302062214.29627-44-jslaby@suse.cz Signed-off-by:
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Jiri Slaby authored
The tty line disciplines don't expect tty_operations::chars_in_buffer to return negative values. Fix the two drivers which violate this. Signed-off-by:
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Jiri Slaby authored
There is no need for 'else' when the 'if' part already returned. This makes tty_chars_in_buffer similar to tty_write_room too. Signed-off-by:
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Jiri Slaby authored
dp, f, and i are only duplicates of gsmld_receive_buf's parameters. Use the parameters directly (cp, fp, and count) and delete these local variables. Signed-off-by:
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Jiri Slaby authored
Forward declarations make the code larger and rewrites harder. Harder as they are often omitted from global changes. Remove forward declarations which are not really needed, i.e. the definition of the function is before its first use. Cc: linuxppc-dev@lists.ozlabs.org Reviewed-by:
Tyrel Datwyler <tyreld@linux.ibm.com> Acked-by:
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by:
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Jiri Slaby authored
Forward declarations make the code larger and rewrites harder. Harder as they are often omitted from global changes. Remove forward declarations which are not really needed, i.e. the definition of the function is before its first use. Signed-off-by:
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Jiri Slaby authored
ptychar was not const, so mark it as such. And move this variable to the only place where it's used. Signed-off-by:
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Jiri Slaby authored
Now that noone checks the return value, switch the return type of tty_unregister_driver to void. We can do that as we always return zero. Generally, drivers are not allowed to call tty_unregister_driver while there are open devices. Signed-off-by:
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Jiri Slaby authored
These drivers check tty_unregister_driver return value. But they don't handle a failure correctly (they free the driver in any case). So stop checking tty_unregister_driver return value and remove also the prints. In the next patch, tty_unregister_driver's return type will be switched to void. Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: linux-xtensa@linux-xtensa.org Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Reviewed-by:
Max Filippov <jcmvbkbc@gmail.com> Acked-by:
David Sterba <dsterba@suse.com> Signed-off-by:
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Jiri Slaby authored
To fix the warning: warning: no previous prototype for 'rs_init' Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: linux-xtensa@linux-xtensa.org Acked-by:
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Jiri Slaby authored
Use DEFINE_TIMER and avoid runtime initialization of the serial_timer. Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: linux-xtensa@linux-xtensa.org Acked-by:
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Jiri Slaby authored
These are likely taken over from amiserial. iss doesn't do anything of that. Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: linux-xtensa@linux-xtensa.org Acked-by:
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Jiri Slaby authored
We already do tty_port_link_device in rs_init, so we don't need to reassign a port to tty->port. It would be too late in tty::ops::open anyway. Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: linux-xtensa@linux-xtensa.org Acked-by:
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Jiri Slaby authored
There is no need to print the information during module load. Neither to print some artificial version. So drop these strings and a print. Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: linux-xtensa@linux-xtensa.org Acked-by:
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Jiri Slaby authored
All these functions are called with a valid tty pointer, no need to check that. Cc: "David S. Miller" <davem@davemloft.net> Cc: sparclinux@vger.kernel.org Signed-off-by:
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