Sven Van Asbroeck 9cc5f232a4 pwm: pca9685: Fix PWM/GPIO inter-operation ... This driver allows pwms to be requested as gpios via gpiolib. Obviously, it should not be allowed to request a GPIO when its corresponding PWM is already requested (and vice versa). So it requires some exclusion code. Given that the PWMm and GPIO cores are not synchronized with respect to each other, this exclusion code will also require proper synchronization. Such a mechanism was in place, but was inadvertently removed by Uwe's clean-up in commit e926b12c61 ("pwm: Clear chip_data in pwm_put()"). Upon revisiting the synchronization mechanism, we found that theoretically, it could allow two threads to successfully request conflicting PWMs/GPIOs. Replace with a bitmap which tracks PWMs in-use, plus a mutex. As long as PWM and GPIO's respective request/free functions modify the in-use bitmap while holding the mutex, proper synchronization will be guaranteed. Reported-by: YueHaibing <yuehaibing@huawei.com> Fixes: e926b12c61 ("pwm: Clear chip_data in pwm_put()") Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: YueHaibing <yuehaibing@huawei.com> Link: https://lkml.org/lkml/2019/5/31/963 Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> [cg: Tested on an i.MX6Q board with two NXP PCA9685 chips] Tested-by: Clemens Gruber <clemens.gruber@pqgruber.com> Reviewed-by: Sven Van Asbroeck <TheSven73@gmail.com> # cg's rebase Link: https://lore.kernel.org/lkml/20200330160238.GD2817345@ulmo/ Signed-off-by: Thierry Reding <thierry.reding@gmail.com>		2020-04-03 21:41:42 +02:00
..
core.c	pwm: Make pwm_apply_state_debug() static	2020-04-03 21:41:09 +02:00
Kconfig	pwm: jz4740: Obtain regmap from parent node	2020-03-30 18:03:09 +02:00
Makefile
pwm-ab8500.c
pwm-atmel-hlcdc.c
pwm-atmel-tcb.c
pwm-atmel.c	pwm: atmel: Implement .get_state()	2020-01-08 13:47:46 +01:00
pwm-bcm-iproc.c	pwm: bcm-iproc: Prevent unloading the driver module while in use	2019-11-08 18:38:06 +01:00
pwm-bcm-kona.c
pwm-bcm2835.c	pwm: bcm2835: Dynamically allocate base	2020-03-30 16:55:25 +02:00
pwm-berlin.c
pwm-brcmstb.c
pwm-clps711x.c
pwm-crc.c
pwm-cros-ec.c	pwm: cros-ec: Cache duty cycle value	2019-12-09 10:05:42 +01:00
pwm-ep93xx.c
pwm-fsl-ftm.c
pwm-hibvt.c
pwm-img.c
pwm-imx-tpm.c	pwm: imx-tpm: Remove unused includes	2020-03-30 16:55:26 +02:00
pwm-imx1.c
pwm-imx27.c	pwm: imx27: Remove unused include of of_device.h	2020-03-30 16:55:26 +02:00
pwm-jz4740.c	pwm: jz4740: Allow selection of PWM channels 0 and 1	2020-03-30 18:03:10 +02:00
pwm-lp3943.c
pwm-lpc18xx-sct.c
pwm-lpc32xx.c
pwm-lpss-pci.c
pwm-lpss-platform.c
pwm-lpss.c
pwm-lpss.h
pwm-mediatek.c
pwm-meson.c	pwm: meson: Remove redundant assignment to variable fin_freq	2020-04-03 21:40:56 +02:00
pwm-mtk-disp.c
pwm-mxs.c	pwm: mxs: Remove unused include of of_address.h	2020-03-30 16:55:27 +02:00
pwm-omap-dmtimer.c	pwm: omap-dmtimer: Implement .apply callback	2020-03-30 18:03:08 +02:00
pwm-pca9685.c	pwm: pca9685: Fix PWM/GPIO inter-operation	2020-04-03 21:41:42 +02:00
pwm-puv3.c
pwm-pxa.c
pwm-rcar.c	pwm: rcar: Fix late Runtime PM enablement	2020-03-30 18:03:05 +02:00
pwm-renesas-tpu.c	pwm: renesas-tpu: Drop confusing registered message	2020-03-30 18:03:06 +02:00
pwm-rockchip.c
pwm-samsung.c
pwm-sifive.c
pwm-spear.c
pwm-sprd.c
pwm-sti.c
pwm-stm32-lp.c
pwm-stm32.c	pwm: stm32: Remove automatic output enable	2020-01-20 13:47:36 +01:00
pwm-stmpe.c
pwm-sun4i.c	pwm: sun4i: Remove redundant needs_delay	2020-03-30 18:03:08 +02:00
pwm-tegra.c	pwm: tegra: Add support for Tegra194	2020-03-30 18:03:04 +02:00
pwm-tiecap.c
pwm-tiehrpwm.c
pwm-twl-led.c
pwm-twl.c
pwm-vt8500.c
pwm-zx.c
sysfs.c