kernel/linux.git/drivers/tty/serial, branch v4.8.16

tty/serial: at91: fix hardware handshake on Atmel platforms

2016-11-18T09:51:49+00:00

commit 9bcffe7575b721d7b6d9b3090fe18809d9806e78 upstream. After commit 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled"), the hardware handshake wasn't functional anymore on Atmel platforms (beside SAMA5D2). To understand why, one has to understand the flag ATMEL_US_USMODE_HWHS first: Before commit 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled"), this flag was never set. Thus, the CTS/RTS where only handled by serial_core (and everything worked just fine). This commit introduced the use of the ATMEL_US_USMODE_HWHS flag, enabling it for all boards when the user space enables flow control. When the ATMEL_US_USMODE_HWHS is set, the Atmel USART controller handles a part of the flow control job: - disable the transmitter when the CTS pin gets high. - drive the RTS pin high when the DMA buffer transfer is completed or PDC RX buffer full or RX FIFO is beyond threshold. (depending on the controller version). NB: This feature is *not* mandatory for the flow control to work. (Nevertheless, it's very useful if low latencies are needed.) Now, the specifics of the ATMEL_US_USMODE_HWHS flag: - For platforms with DMAC and no FIFOs (sam9x25, sam9x35, sama5D3, sama5D4, sam9g15, sam9g25, sam9g35)* this feature simply doesn't work. ( source: https://lkml.org/lkml/2016/9/7/598 ) Tested it on sam9g35, the RTS pins always stays up, even when RXEN=1 or a new DMA transfer descriptor is set. => ATMEL_US_USMODE_HWHS must not be used for those platforms - For platforms with a PDC (sam926{0,1,3}, sam9g10, sam9g20, sam9g45, sam9g46)*, there's another kind of problem. Once the flag ATMEL_US_USMODE_HWHS is set, the RTS pin can't be driven anymore via RTSEN/RTSDIS in USART Control Register. The RTS pin can only be driven by enabling/disabling the receiver or setting RCR=RNCR=0 in the PDC (Receive (Next) Counter Register). => Doing this is beyond the scope of this patch and could add other bugs, so the original (and working) behaviour should be set for those platforms (meaning ATMEL_US_USMODE_HWHS flag should be unset). - For platforms with a FIFO (sama5d2)*, the RTS pin is driven according to the RX FIFO thresholds, and can be also driven by RTSEN/RTSDIS in USART Control Register. No problem here. (This was the use case of commit 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled")) NB: If the CTS pin declared as a GPIO in the DTS, (for instance cts-gpios = <&pioA PIN_PB31 GPIO_ACTIVE_LOW>), the transmitter will be disabled. => ATMEL_US_USMODE_HWHS flag can be set for this platform ONLY IF the CTS pin is not a GPIO. So, the only case when ATMEL_US_USMODE_HWHS can be enabled is when (atmel_use_fifo(port) && !mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS)) Tested on all Atmel USART controller flavours: AT91SAM9G35-CM (DMAC flavour), AT91SAM9G20-EK (PDC flavour), SAMA5D2xplained (FIFO flavour). * the list may not be exhaustive Fixes: 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled") Signed-off-by: Richard Genoud Acked-by: Alexandre Belloni Acked-by: Cyrille Pitchen Acked-by: Uwe Kleine-König [nicolas.ferre@atmel.com: adapt to 4.4.x kernel for stable by adding the atmel_port variable declaration which was missing] Signed-off-by: Nicolas Ferre Signed-off-by: Greg Kroah-Hartman

serial: 8250_port: fix runtime PM use in __do_stop_tx_rs485()

2016-10-22T10:40:21+00:00

commit b3965767d86cf4534dfe1affbde0453d3224ed7f upstream. There are calls to serial8250_rpm_{get|put}() in __do_stop_tx_rs485() that are certainly placed in a wrong location. I dunno how it had been tested with runtime PM enabled because it is obvious "sleep in atomic context" error. Besides that serial8250_rpm_get() is called immediately after an IO just happened. It implies that the device is already powered on, see implementation of serial8250_em485_rts_after_send() and serial8250_clear_fifos() for the details. There is no bug have been seen due to, as I can guess, use of auto suspend mode when scheduled transaction to suspend is invoked quite lately than it's needed for a few writes to the port. It might be possible to trigger a warning if stop_tx_timer fires when device is suspended. Refactor the code to use runtime PM only in case of timer function. Fixes: 0c66940d584d ("tty/serial/8250: fix RS485 half-duplex RX") Cc: "Matwey V. Kornilov" Tested-by: Yegor Yefremov Signed-off-by: Andy Shevchenko Signed-off-by: Greg Kroah-Hartman

serial: 8250_dw: Check the data->pclk when get apb_pclk

2016-10-22T10:40:21+00:00

commit e16b46f190a22587898b331f9d58583b0b166c9a upstream. It should check the data->pclk, not data->clk when get apb_pclk. Fixes: c8ed99d4f6a8("serial: 8250_dw: Add support for deferred probing") Signed-off-by: Kefeng Wang Tested-by: Andy Shevchenko Signed-off-by: Greg Kroah-Hartman

BUG: atmel_serial: Interrupts not disabled on close

2016-10-22T10:40:21+00:00

commit 0ae9fdefb6c37237d826d6195e27810ffcc0b6e0 upstream. Since commit 18dfef9c7f87 ("serial: atmel: convert to irq handling provided mctrl-gpio"), interrupts from GPIOs are not disabled any more when the serial port is closed, leading to an oops when the one of the input pin is toggled (CTS/DSR/DCD/RNG). This is only the case if those pins are used as GPIOs, i.e. declared like that: usart1: serial@f8020000 { /* CTS and DTS will be handled by GPIO */ status = "okay"; rts-gpios = <&pioB 17 GPIO_ACTIVE_LOW>; cts-gpios = <&pioB 16 GPIO_ACTIVE_LOW>; dtr-gpios = <&pioB 14 GPIO_ACTIVE_LOW>; dsr-gpios = <&pioC 31 GPIO_ACTIVE_LOW>; rng-gpios = <&pioB 12 GPIO_ACTIVE_LOW>; dcd-gpios = <&pioB 15 GPIO_ACTIVE_LOW>; }; That's because modem interrupts used to be freed in atmel_shutdown(). After commit 18dfef9c7f87 ("serial: atmel: convert to irq handling provided mctrl-gpio"), this code was just removed. Calling atmel_disable_ms() disables the interrupts and everything works fine again. Tested on at91sam9g35-cm (This patch doesn't apply on -stable kernels, fixes for 4.4 and 4.7 will be sent after this one is applied.) Signed-off-by: Richard Genoud Fixes: 18dfef9c7f87 ("serial: atmel: convert to irq handling provided mctrl-gpio") Acked-by: Nicolas Ferre Acked-by: Uwe Kleine-König Signed-off-by: Greg Kroah-Hartman

serial: imx: Fix DCD reading

2016-10-22T10:40:21+00:00

commit 4b75f80003617fe35771a9e27022e8fbd6a41875 upstream. The USR2_DCDIN bit is tested for in register usr1. As the name suggests the usr2 register should be used instead. This fixes reading the Carrier detect status. Signed-off-by: Sascha Hauer Fixes: 90ebc4838666 ("serial: imx: repair and complete handshaking") Acked-by: Uwe Kleine-König Reviewed-by: Fabio Estevam Signed-off-by: Greg Kroah-Hartman

serial: 8250: added acces i/o products quad and octal serial cards

2016-08-31T14:28:26+00:00

Added devices ids for acces i/o products quad and octal serial cards that make use of existing Pericom PI7C9X7954 and PI7C9X7958 configurations . Signed-off-by: Jimi Damon Cc: stable Signed-off-by: Greg Kroah-Hartman

serial: 8250_mid: fix divide error bug if baud rate is 0

2016-08-31T13:49:26+00:00

Since the commit c1a67b48f6a5 ("serial: 8250_pci: replace switch-case by formula for Intel MID"), the 8250 driver crashes in the byt_set_termios() function with a divide error. This is caused by the fact that a baud rate of 0 (B0) is not handled properly. Fix it by falling back to B9600 in this case. Reported-by: "Mendez Salinas, Fernando" Fixes: c1a67b48f6a5 ("serial: 8250_pci: replace switch-case by formula for Intel MID") Cc: stable@vger.kernel.org Signed-off-by: Andy Shevchenko Signed-off-by: Greg Kroah-Hartman

Revert "tty/serial/8250: use mctrl_gpio helpers"

2016-08-31T13:36:01+00:00

Serial console is broken in v4.8-rcX. Mika and I independently bisected down to commit 4ef03d328769 ("tty/serial/8250: use mctrl_gpio helpers"). Since neither author nor anyone else didn't propose a solution we better revert it for now. This reverts commit 4ef03d328769eddbfeca1f1c958fdb181a69c341. Link: https://lkml.kernel.org/r/20160809130229.GN1729@lahna.fi.intel.com Signed-off-by: Andy Shevchenko Tested-by: Heikki Krogerus Tested-by: Mika Westerberg Signed-off-by: Greg Kroah-Hartman

8250/fintek: rename IRQ_MODE macro

2016-08-18T16:16:13+00:00

A bugfix for the fintek driver required defining some macros, but one of them clashes with a system header on ARM: drivers/tty/serial/8250/8250_fintek.c:34:0: error: "IRQ_MODE" redefined [-Werror] #define IRQ_MODE 0x70 In file included from /git/arm-soc/arch/arm/include/asm/ptrace.h:13:0, from /git/arm-soc/arch/arm/include/asm/irqflags.h:6, from /git/arm-soc/include/linux/irqflags.h:15, from /git/arm-soc/arch/arm/include/asm/bitops.h:27, from /git/arm-soc/include/linux/bitops.h:36, from /git/arm-soc/include/linux/kernel.h:10, from /git/arm-soc/include/linux/list.h:8, from /git/arm-soc/include/linux/module.h:9, from /git/arm-soc/drivers/tty/serial/8250/8250_fintek.c:11: arch/arm/include/uapi/asm/ptrace.h:55:0: note: this is the location of the previous definition This renames the newly introduced 'IRQ_MODE' macro to FINTEK_IRQ_MODE. Signed-off-by: Arnd Bergmann Fixes: 4da22f1418cb ("serial: 8250_fintek: fix the mismatched IRQ mode") Link: https://patchwork.kernel.org/patch/9200119/ Acked-by: Ji-Ze Hong (Peter Hong) Acked-by: Ricardo Ribalda Delgado Signed-off-by: Greg Kroah-Hartman

tree-wide: replace config_enabled() with IS_ENABLED()

2016-08-04T12:50:07+00:00

The use of config_enabled() against config options is ambiguous. In practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the author might have used it for the meaning of IS_ENABLED(). Using IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc. makes the intention clearer. This commit replaces config_enabled() with IS_ENABLED() where possible. This commit is only touching bool config options. I noticed two cases where config_enabled() is used against a tristate option: - config_enabled(CONFIG_HWMON) [ drivers/net/wireless/ath/ath10k/thermal.c ] - config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE) [ drivers/gpu/drm/gma500/opregion.c ] I did not touch them because they should be converted to IS_BUILTIN() in order to keep the logic, but I was not sure it was the authors' intention. Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada Acked-by: Kees Cook Cc: Stas Sergeev Cc: Matt Redfearn Cc: Joshua Kinard Cc: Jiri Slaby Cc: Bjorn Helgaas Cc: Borislav Petkov Cc: Markos Chandras Cc: "Dmitry V. Levin" Cc: yu-cheng yu Cc: James Hogan Cc: Brian Gerst Cc: Johannes Berg Cc: Peter Zijlstra Cc: Al Viro Cc: Will Drewry Cc: Nikolay Martynov Cc: Huacai Chen Cc: "H. Peter Anvin" Cc: Thomas Gleixner Cc: Daniel Borkmann Cc: Leonid Yegoshin Cc: Rafal Milecki Cc: James Cowgill Cc: Greg Kroah-Hartman Cc: Ralf Baechle Cc: Alex Smith Cc: Adam Buchbinder Cc: Qais Yousef Cc: Jiang Liu Cc: Mikko Rapeli Cc: Paul Gortmaker Cc: Denys Vlasenko Cc: Brian Norris Cc: Hidehiro Kawai Cc: "Luis R. Rodriguez" Cc: Andy Lutomirski Cc: Ingo Molnar Cc: Dave Hansen Cc: "Kirill A. Shutemov" Cc: Roland McGrath Cc: Paul Burton Cc: Kalle Valo Cc: Viresh Kumar Cc: Tony Wu Cc: Huaitong Han Cc: Sumit Semwal Cc: Alexei Starovoitov Cc: Juergen Gross Cc: Jason Cooper Cc: "David S. Miller" Cc: Oleg Nesterov Cc: Andrea Gelmini Cc: David Woodhouse Cc: Marc Zyngier Cc: Rabin Vincent Cc: "Maciej W. Rozycki" Cc: David Daney Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds