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alistair23-linux/drivers/tty/serial
Alexander Sverdlin bb07f4c93e serial: 8250_omap: Avoid FIFO corruption caused by MDR1 access
commit d96f04d347 upstream.

It has been observed that once per 300-1300 port openings the first
transmitted byte is being corrupted on AM3352 ("v" written to FIFO appeared
as "e" on the wire). It only happened if single byte has been transmitted
right after port open, which means, DMA is not used for this transfer and
the corruption never happened afterwards.

Therefore I've carefully re-read the MDR1 errata (link below), which says
"when accessing the MDR1 registers that causes a dummy under-run condition
that will freeze the UART in IrDA transmission. In UART mode, this may
corrupt the transferred data". Strictly speaking,
omap_8250_mdr1_errataset() performs a read access and if the value is the
same as should be written, exits without errata-recommended FIFO reset.

A brief check of the serial_omap_mdr1_errataset() from the competing
omap-serial driver showed it has no read access of MDR1. After removing the
read access from omap_8250_mdr1_errataset() the data corruption never
happened any more.

Link: https://www.ti.com/lit/er/sprz360i/sprz360i.pdf
Fixes: 61929cf016 ("tty: serial: Add 8250-core based omap driver")
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Link: https://lore.kernel.org/r/20201210055257.1053028-1-alexander.sverdlin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-21 13:27:06 +01:00
..
8250 serial: 8250_omap: Avoid FIFO corruption caused by MDR1 access 2020-12-21 13:27:06 +01:00
cpm_uart tty: cpm_uart: drop unused iflag macro 2019-05-24 10:09:16 +02:00
jsm tty: add SPDX identifiers to Kconfig and Makefiles 2019-04-04 18:48:43 +02:00
21285.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
Kconfig tty: serial: earlycon dependency 2020-10-29 09:57:37 +01:00
Makefile TTY/Serial driver changes for 5.4-rc1 2019-09-18 10:50:47 -07:00
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: pl011: Fix lockdep splat when handling magic-sysrq interrupt 2020-11-01 12:01:06 +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: set UART_CS_{RX,TX}_READY_ORIDE 2020-03-12 13:00:10 +01:00
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: manage shutdown in case of RS485 or ISO7816 mode 2020-02-28 17:22:19 +01:00
atmel_serial.h tty/serial: atmel: add ISO7816 support 2018-10-02 13:38:55 -07:00
bcm63xx_uart.c MIPS changes for 4.15 2017-11-15 11:36:08 -08:00
clps711x.c serial: clps711x: Remove board support 2019-01-08 16:55:18 +01:00
digicolor-usart.c tty/serial: digicolor: Fix digicolor-usart already registered warning 2019-06-10 19:08:31 +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-riscv-sbi.c tty/serial: use uart_console_write in the RISC-V SBL early console 2019-01-23 15:41:50 -08:00
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_linflexuart.c tty: serial: linflexuart: Fix magic SysRq handling 2019-10-04 15:02:28 +02:00
fsl_lpuart.c tty: serial: fsl_lpuart: LS1021A has a FIFO size of 16 words, like LS1028A 2020-11-10 12:37:33 +01:00
icom.c tty: serial: Remove call to memset after pci_alloc_consistent 2019-09-04 12:43:44 +02:00
icom.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
ifx6x60.c serial: ifx6x60: add missed pm_runtime_disable 2019-12-13 08:42:25 +01:00
ifx6x60.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
imx.c tty: serial: imx: keep console clocks always on 2020-11-24 13:29:20 +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
kgdb_nmi.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
kgdboc.c kgdboc: Use a platform device to handle tty drivers showing up late 2020-06-22 09:31:06 +02:00
lantiq.c serial: lantiq: Add support for Lightning Mountain SoC 2019-09-04 12:43:53 +02:00
lpc32xx_hs.c TTY/Serial driver changes for 5.4-rc1 2019-09-18 10:50:47 -07:00
max310x.c serial: max310x: turn off transmitter before activating AutoCTS or auto transmitter flow control 2019-09-05 09:57:44 +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 drivers: Remove explicit invocations of mmiowb() 2019-04-08 12:01:02 +01:00
meson_uart.c tty: serial: meson: if no alias specified use an available id 2019-01-18 11:22:22 +01:00
milbeaut_usio.c serial: milbeaut_usio: Fix error handling in probe and remove 2019-04-29 16:20:24 +02:00
mpc52xx_uart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
mps2-uart.c serial: mps2-uart: Add parentheses around conditional in mps2_uart_shutdown 2019-01-31 19:34:10 +01:00
msm_serial.c tty: serial: msm_serial: Fix lockup for sysrq and oops 2020-01-09 10:20:05 +01:00
mux.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
mvebu-uart.c tty:serial:mvebu-uart:fix a wrong return 2020-03-12 13:00:20 +01:00
mxs-auart.c serial: mxs-auart: add missed iounmap() in probe failure and remove 2020-07-22 09:33:11 +02:00
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: owl: add "much needed" clk_prepare_enable() 2020-04-29 16:33:14 +02:00
pch_uart.c tty: serial: pch_uart: correct usage of dma_unmap_sg 2020-01-17 19:48:55 +01:00
pic32_uart.c serial: set suppress_bind_attrs flag only if builtin 2018-11-09 09:07:17 -08:00
pic32_uart.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
pmac_zilog.c tty: Use of_node_name_{eq,prefix} for node name comparisons 2018-12-17 16:12:17 +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 serial: qcom_geni_serial: To correct QUP Version detection logic 2020-11-01 12:01:06 +01:00
rda-uart.c tty: serial: rda: Fix the link time qualifier of 'rda_uart_exit()' 2019-10-04 15:01:15 +02:00
rp2.c treewide: devm_kzalloc() -> devm_kcalloc() 2018-06-12 16:19:22 -07:00
sa1100.c serial: sa1100: add note about modem control signals 2019-06-04 12:56:33 +01:00
samsung.c tty: serial: samsung: Correct clock selection logic 2020-10-01 13:18:00 +02:00
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 Merge 5.1-rc6 into tty-next 2019-04-21 23:20:08 +02:00
sccnxp.c tty: Remove dev_err() usage after platform_get_irq() 2019-09-04 12:43:49 +02:00
serial-tegra.c serial: tegra: fix CREAD handling for PIO 2020-07-29 10:18:42 +02:00
serial_core.c tty: link tty and port before configuring it as console 2020-01-14 20:08:33 +01:00
serial_mctrl_gpio.c serial: mctrl_gpio: Check for NULL pointer 2019-10-07 13:21:54 +02:00
serial_mctrl_gpio.h serial: mctrl_gpio: Avoid probe failures in case of missing gpiolib 2019-09-04 12:43:50 +02:00
serial_txx9.c serial: txx9: add missing platform_driver_unregister() on error in serial_txx9_init 2020-11-10 12:37:32 +01:00
sh-sci.c serial: sh-sci: Make sure status register SCxSR is read in correct sequence 2020-04-29 16:33:24 +02:00
sh-sci.h serial: sh-sci: Support for HSCIF RX sampling point adjustment 2018-04-23 10:08:18 +02:00
sifive.c tty: sifive: Finish transmission before changing the clock 2020-10-01 13:17:42 +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
sprd_serial.c serial: sprd: Fix a dereference warning 2020-04-02 15:10:59 +02:00
st-asc.c tty: serial: simplify getting .drvdata 2018-04-22 17:29:43 +02:00
stm32-usart.c serial: stm32: avoid kernel warning on absence of optional IRQ 2020-09-03 11:27:03 +02:00
stm32-usart.h serial: stm32: add support of RX FIFO threshold 2019-06-21 11:17:36 +02:00
suncore.c tty: Use of_node_name_{eq,prefix} for node name comparisons 2018-12-17 16:12:17 +01:00
sunhv.c sunhv: Fix device naming inconsistency between sunhv_console and sunhv_reg 2019-06-13 14:04:37 -07:00
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 TTY/Serial driver patches for 4.21-rc1 2018-12-28 20:33:54 -08:00
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
tegra-tcu.c serial: Add Tegra Combined UART driver 2019-01-30 09:31:31 +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 serial: uartlite: fix exit path null pointer 2019-10-04 15:02:46 +02:00
ucc_uart.c docs: serial: move it to the driver-api 2019-07-15 11:03:03 -03:00
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: Wait for tx_empty in console setup 2020-10-01 13:17:55 +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