linux-uconsole/drivers/tty/serial
Geert Uytterhoeven d03aeb8d6b serial: sh-sci: Fix TX DMA buffer flushing and workqueue races
[ Upstream commit 8493eab026 ]

When uart_flush_buffer() is called, the .flush_buffer() callback zeroes
the tx_dma_len field.  This may race with the work queue function
handling transmit DMA requests:

  1. If the buffer is flushed before the first DMA API call,
     dmaengine_prep_slave_single() may be called with a zero length,
     causing the DMA request to never complete, leading to messages
     like:

        rcar-dmac e7300000.dma-controller: Channel Address Error happen

     and, with debug enabled:

	sh-sci e6e88000.serial: sci_dma_tx_work_fn: ffff800639b55000: 0...0, cookie 126

     and DMA timeouts.

  2. If the buffer is flushed after the first DMA API call, but before
     the second, dma_sync_single_for_device() may be called with a zero
     length, causing the transmit data not to be flushed to RAM, and
     leading to stale data being output.

Fix this by:
  1. Letting sci_dma_tx_work_fn() return immediately if the transmit
     buffer is empty,
  2. Extending the critical section to cover all DMA preparational work,
     so tx_dma_len stays consistent for all of it,
  3. Using local copies of circ_buf.head and circ_buf.tail, to make sure
     they match the actual operation above.

Reported-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Suggested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Link: https://lore.kernel.org/r/20190624123540.20629-2-geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-31 07:27:04 +02:00
..
8250 serial: 8250: Fix TX interrupt handling condition 2019-07-31 07:27:00 +02:00
cpm_uart tty: serial: cpm_uart - fix init when SMC is relocated 2019-07-31 07:26:57 +02:00
jsm tty: serial: jsm: remove redundant pointer ch 2018-07-13 15:36:32 +02:00
21285.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
altera_jtaguart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
altera_uart.c serial: altera: set RRDY flag also without irq 2018-02-28 13:30:09 +01:00
amba-pl010.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
amba-pl011.c serial: set suppress_bind_attrs flag only if builtin 2019-01-26 09:32:34 +01:00
amba-pl011.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
apbuart.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
apbuart.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ar933x_uart.c serial: ar933x_uart: Fix build failure with disabled console 2019-05-04 09:20:13 +02:00
arc_uart.c serial: arc_uart: Fix out-of-bounds access through DT alias 2018-02-28 15:29:59 +01:00
atmel_serial.c tty/serial: atmel: RS485 HD w/DMA: enable RX after TX is stopped 2019-04-05 22:32:55 +02:00
atmel_serial.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
bcm63xx_uart.c MIPS changes for 4.15 2017-11-15 11:36:08 -08:00
clps711x.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
digicolor-usart.c tty/serial: digicolor: Fix digicolor-usart already registered warning 2019-07-31 07:26:59 +02:00
dz.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
dz.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
earlycon-arm-semihost.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
earlycon.c earlycon: Remove hardcoded port->uartclk initialization in of_setup_earlycon 2018-05-14 13:41:05 +02:00
efm32-uart.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
fsl_lpuart.c serial: fsl_lpuart: fix maximum acceptable baud rate with over-sampling 2019-03-05 17:58:49 +01:00
icom.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
icom.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
ifx6x60.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
ifx6x60.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
imx.c serial: imx: fix locking in set_termios() 2019-07-31 07:27:01 +02:00
ioc3_serial.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
ioc4_serial.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
ip22zilog.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
ip22zilog.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig tty: serial: drop ATH79 specific SoC symbols 2018-05-14 13:51:12 +02:00
kgdb_nmi.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
kgdboc.c Disable kgdboc failed by echo space to /sys/module/kgdboc/parameters/kgdboc 2019-04-03 06:26:26 +02:00
lantiq.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
lpc32xx_hs.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
Makefile TTY/Serial driver patches for 4.17-rc1 2018-04-04 18:43:49 -07:00
max310x.c tty: max310x: Fix invalid baudrate divisors calculator 2019-07-31 07:26:57 +02:00
max3100.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
mcf.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
men_z135_uart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
meson_uart.c tty: serial: meson: fix typo in the "stop bit" register definition 2017-11-28 15:32:33 +01:00
mpc52xx_uart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
mps2-uart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
mpsc.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
msm_serial.c tty: serial: msm_serial: avoid system lockup condition 2019-07-31 07:26:59 +02:00
mux.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
mvebu-uart.c serial: mvebu-uart: Fix to avoid a potential NULL pointer dereference 2019-04-03 06:26:25 +02:00
mxs-auart.c tty: mxs-auart: fix a potential NULL pointer dereference 2019-04-03 06:26:24 +02:00
netx-serial.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
omap-serial.c tty: omap-serial: Fix initial on-boot RTS GPIO level 2018-01-09 16:45:17 +01:00
owl-uart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
pch_uart.c treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
pic32_uart.c serial: set suppress_bind_attrs flag only if builtin 2019-01-26 09:32:34 +01:00
pic32_uart.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
pmac_zilog.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
pmac_zilog.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pnx8xxx_uart.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
pxa.c serial: pxa: Fix an error handling path in 'serial_pxa_probe()' 2018-06-28 21:07:54 +09:00
qcom_geni_serial.c tty: serial: qcom_geni_serial: Initialize baud in qcom_geni_console_setup 2019-04-03 06:26:24 +02:00
rp2.c treewide: devm_kzalloc() -> devm_kcalloc() 2018-06-12 16:19:22 -07:00
sa1100.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
samsung.c tty: serial: samsung: Properly set flags in autoCTS mode 2019-02-12 19:47:11 +01:00
samsung.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
sb1250-duart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
sc16is7xx.c sc16is7xx: move label 'err_spi' to correct section 2019-07-10 09:53:46 +02:00
sccnxp.c headers: separate linux/mod_devicetable.h from linux/platform_device.h 2018-07-07 17:52:26 +02:00
serial-tegra.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
serial_core.c tty: serial_core: Set port active bit in uart_port_activate 2019-07-31 07:27:01 +02:00
serial_ks8695.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
serial_mctrl_gpio.c serial: mctrl_gpio: Check if GPIO property exisits before requesting it 2019-07-31 07:27:01 +02:00
serial_mctrl_gpio.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
serial_txx9.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
sh-sci.c serial: sh-sci: Fix TX DMA buffer flushing and workqueue races 2019-07-31 07:27:04 +02:00
sh-sci.h serial: sh-sci: Support for HSCIF RX sampling point adjustment 2018-04-23 10:08:18 +02:00
sirfsoc_uart.c serial: sirf: Fix out-of-bounds access through DT alias 2018-02-28 15:30:00 +01:00
sirfsoc_uart.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
sn_console.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
sprd_serial.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
st-asc.c tty: serial: simplify getting .drvdata 2018-04-22 17:29:43 +02:00
stm32-usart.c serial: stm32: fix initialization of RS485 mode 2018-03-15 17:39:43 +01:00
stm32-usart.h serial: stm32: add support for RS485 hardware control mode 2018-03-14 13:35:37 +01:00
suncore.c drivers/tty: add missing of_node_put() 2018-12-21 14:15:18 +01:00
sunhv.c sunhv: Fix device naming inconsistency between sunhv_console and sunhv_reg 2019-06-22 08:15:14 +02:00
sunsab.c treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
sunsab.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sunsu.c serial/sunsu: fix refcount leak 2019-01-13 09:51:03 +01:00
sunzilog.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
sunzilog.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
timbuart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
timbuart.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
uartlite.c tty: serial: uartlite: Add support for suspend and resume 2018-08-02 10:08:43 +02:00
ucc_uart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
vr41xx_siu.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
vt8500_serial.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
xilinx_uartps.c serial: uartps: console_setup() can't be placed to init section 2019-04-20 09:16:01 +02:00
zs.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
zs.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00