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13dc04d0e5
linux/drivers/tty/serial
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Tony Lindgren 13dc04d0e5 serial: 8250: omap: Fix idling of clocks for unused uarts 
I noticed that unused UARTs won't necessarily idle properly always
unless at least one byte tx transfer is done first.

After some debugging I narrowed down the problem to the scr register
dma configuration bits that need to be set before softreset for the
clocks to idle. Unless we do this, the module clkctrl idlest bits
may be set to 1 instead of 3 meaning the clock will never idle and
is blocking deeper idle states for the whole domain.

This might be related to the configuration done by the bootloader
or kexec booting where certain configurations cause the 8250 or
the clkctrl clock to jam in a way where setting of the scr bits
and reset is needed to clear it. I've tried diffing the 8250
registers for the various modes, but did not see anything specific.
So far I've only seen this on omap4 but I'm suspecting this might
also happen on the other clkctrl using SoCs considering they
already have a quirk enabled for UART_ERRATA_CLOCK_DISABLE.

Let's fix the issue by configuring scr before reset for basic dma
even if we don't use it. The scr register will be reset when we do
softreset few lines after, and we restore scr on resume. We should
do this for all the SoCs with UART_ERRATA_CLOCK_DISABLE quirk flag
set since the ones with UART_ERRATA_CLOCK_DISABLE are all based
using clkctrl similar to omap4.

Looks like both OMAP_UART_SCR_DMAMODE_1 | OMAP_UART_SCR_DMAMODE_CTL
bits are needed for the clkctrl to idle after a softreset.

And we need to add omap4 to also use the UART_ERRATA_CLOCK_DISABLE
for the related workaround to be enabled. This same compatible
value will also be used for omap5.

Fixes: cdb929e445 ("serial: 8250_omap: workaround errata around idling UART after using DMA")
Cc: Keerthy <j-keerthy@ti.com>
Cc: Matthijs van Duin <matthijsvanduin@gmail.com>
Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 13:51:12 +02:00
..
8250 serial: 8250: omap: Fix idling of clocks for unused uarts 2018-05-14 13:51:12 +02:00
cpm_uart TTY/Serial patches for 4.15-rc1 2017-11-13 21:05:31 -08:00
jsm tty: serial: jsm: Add one check against NULL pointer dereference 2018-01-09 16:37:03 +01:00
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 tty: pl011: Avoid spuriously stuck-off interrupts 2018-05-14 13:41:05 +02:00
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 tty: serial: Remove redundant license text 2017-11-08 13:08:12 +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: use port->name as name in request_irq() 2018-05-14 13:48:28 +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: Remove redundant license text 2017-11-08 13:08:12 +01:00
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 out-of-bounds access through DT alias 2018-02-28 15:29:59 +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: dma_unmap_sg buffers on shutdown 2018-05-14 13:48:28 +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 Modules updates for v4.15 2017-11-15 13:46:33 -08:00
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 gpio: serial: max310x: Use HW type for gpio_chip's label 2018-02-28 13:40:22 +01:00
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: Add __maybe_unused to suspend/resume callbacks 2018-05-14 13:41:05 +02:00
mux.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
mvebu-uart.c Merge 4.17-rc3 into tty-next 2018-04-30 05:14:55 -07:00
mxs-auart.c serial: mxs-auart: disable clks of Alphascale ASM9260 2018-03-09 11:01:19 -08:00
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 tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
pic32_uart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +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 out-of-bounds access through serial port index 2018-02-28 15:29:59 +01:00
qcom_geni_serial.c tty: serial: qcom_geni_serial: Add early console support 2018-05-14 13:44:55 +02:00
rp2.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
sa1100.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
samsung.c serial: samsung: fix maxburst parameter for DMA transactions 2018-05-14 13:41:05 +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 sc16is7xx: Check for an error when the clock is enabled. 2018-04-25 14:56:12 +02:00
sccnxp.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
serial_core.c serial: Introduce UPSTAT_SYNC_FIFO for synchronised FIFOs 2018-04-23 10:16:50 +02:00
serial_ks8695.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
serial_mctrl_gpio.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
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
serial-tegra.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
sh-sci.c serial: sh-sci: Use spin_{try}lock_irqsave instead of open coding version 2018-05-14 13:51:11 +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 tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
sunhv.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
sunsab.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
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: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +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: Remove redundant license text 2017-11-08 13:08:12 +01:00
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 Merge 4.17-rc3 into tty-next 2018-04-30 05:14:55 -07:00
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