linux_dsm_epyc7002/drivers/pwm
Hans de Goede 2153bbc12f pwm: lpss: Only set update bit if we are actually changing the settings
According to the datasheet the update bit must be set if the on-time-div
or the base-unit changes.

Now that we properly order device resume on Cherry Trail so that the GFX0
_PS0 method no longer exits with an error, we end up with a sequence of
events where we are writing the same values twice in a row.

First the _PS0 method restores the duty cycle of 0% the GPU driver set
on suspend and then the GPU driver first updates just the enabled bit in
the pwm_state from 0 to 1, causing us to write the same values again,
before restoring the pre-suspend duty-cycle in a separate pwm_apply call.

When writing the update bit the second time, without changing any of
the values the update bit clears immediately / instantly, instead of
staying 1 for a while as usual. After this the next setting of the update
bit seems to be ignored, causing the restoring of the pre-suspend
duty-cycle to not get applied. This makes the backlight come up with
a 0% dutycycle after suspend/resume.

Any further brightness changes after this do work.

This commit moves the setting of the update bit into pwm_lpss_prepare()
and only sets the bit if we have actually changed any of the values.

This avoids the setting of the update bit the second time we configure
the PWM to 0% dutycycle, this fixes the backlight coming up with 0%
duty-cycle after a suspend/resume.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-10-16 13:16:15 +02:00
..
core.c
Kconfig pwm: Enable TI ECAP driver for ARCH_K3 2018-10-16 13:14:52 +02:00
Makefile
pwm-ab8500.c
pwm-atmel-hlcdc.c
pwm-atmel-tcb.c pwm: simplify getting .drvdata 2018-04-30 10:40:57 +02:00
pwm-atmel.c
pwm-bcm2835.c
pwm-bcm-iproc.c
pwm-bcm-kona.c
pwm-berlin.c pwm: berlin: Don't use broken prescaler values 2018-07-09 18:57:03 +02:00
pwm-brcmstb.c
pwm-clps711x.c
pwm-crc.c
pwm-cros-ec.c pwm: cros-ec: Switch to SPDX identifier 2018-07-09 19:02:23 +02:00
pwm-ep93xx.c
pwm-fsl-ftm.c pwm: fsl-ftm: Enable support for the new SoC i.MX8QM 2018-07-09 19:08:26 +02:00
pwm-hibvt.c
pwm-img.c
pwm-imx.c pwm: imx: Switch to SPDX identifier 2018-07-09 18:59:14 +02:00
pwm-jz4740.c
pwm-lp3943.c treewide: devm_kzalloc() -> devm_kcalloc() 2018-06-12 16:19:22 -07:00
pwm-lpc18xx-sct.c
pwm-lpc32xx.c
pwm-lpss-pci.c
pwm-lpss-platform.c pwm: lpss: Force runtime-resume on suspend on Cherry Trail 2018-10-16 13:15:57 +02:00
pwm-lpss.c pwm: lpss: Only set update bit if we are actually changing the settings 2018-10-16 13:16:15 +02:00
pwm-lpss.h pwm: lpss: Force runtime-resume on suspend on Cherry Trail 2018-10-16 13:15:57 +02:00
pwm-mediatek.c pwm: mediatek: Add MT7628 support 2018-08-20 11:36:07 +02:00
pwm-meson.c pwm: meson: Fix mux clock names 2018-08-20 11:32:25 +02:00
pwm-mtk-disp.c
pwm-mxs.c pwm: mxs: Switch to SPDX identifier 2018-07-12 09:03:06 +02:00
pwm-omap-dmtimer.c pwm: omap-dmtimer: Return -EPROBE_DEFER if no dmtimer platform data 2018-08-20 11:32:19 +02:00
pwm-pca9685.c
pwm-puv3.c
pwm-pxa.c
pwm-rcar.c pwm: Use SPDX identifier for Renesas drivers 2018-10-12 13:35:45 +02:00
pwm-renesas-tpu.c pwm: Use SPDX identifier for Renesas drivers 2018-10-12 13:35:45 +02:00
pwm-rockchip.c
pwm-samsung.c
pwm-spear.c
pwm-sti.c
pwm-stm32-lp.c pwm: stm32-lp: Remove useless loop in stm32_pwm_lp_remove() 2018-08-20 11:32:25 +02:00
pwm-stm32.c pwm: Changes for v4.18-rc1 2018-06-14 16:25:43 +09:00
pwm-stmpe.c
pwm-sun4i.c
pwm-tegra.c pwm: tegra: Remove gratuituous blank line 2018-09-26 16:01:39 +02:00
pwm-tiecap.c
pwm-tiehrpwm.c pwm: tiehrpwm: Fix disabling of output of PWMs 2018-07-09 18:58:22 +02:00
pwm-tipwmss.c
pwm-twl-led.c
pwm-twl.c
pwm-vt8500.c
pwm-zx.c
sysfs.c pwm: Send a uevent on the pwmchip device upon channel sysfs (un)export 2018-10-12 13:51:33 +02:00