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authorVladimir Zapolskiy <vladimir_zapolskiy@mentor.com>2014-10-11 17:46:26 +0400
committerLee Jones <lee.jones@linaro.org>2014-11-10 17:42:18 +0300
commitedf387b6d1a6993103ec95ed934a6daf559535f4 (patch)
tree2510d4c001381b7eefcdcdd0a2bf16b77c00f579 /drivers/video/backlight
parent0df1f2487d2f0d04703f142813d53615d62a1da4 (diff)
downloadlinux-edf387b6d1a6993103ec95ed934a6daf559535f4.tar.xz
backlight: pwm: Clean-up pwm requested using legacy API
If PWM device is requested by means of legacy API pwm_request(), its resources are not freed on module unbind, which may cause an oops on access, e.g. by reading /sys/kernel/debug/pwm. Reported-by: Dmitry Eremin-Solenikov <dmitry_eremin@mentor.com> Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
Diffstat (limited to 'drivers/video/backlight')
-rw-r--r--drivers/video/backlight/pwm_bl.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index cb5ae4c08469..3a145a643e0d 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -34,6 +34,7 @@ struct pwm_bl_data {
struct regulator *power_supply;
struct gpio_desc *enable_gpio;
unsigned int scale;
+ bool legacy;
int (*notify)(struct device *,
int brightness);
void (*notify_after)(struct device *,
@@ -274,7 +275,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
pb->pwm = devm_pwm_get(&pdev->dev, NULL);
if (IS_ERR(pb->pwm)) {
dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n");
-
+ pb->legacy = true;
pb->pwm = pwm_request(data->pwm_id, "pwm-backlight");
if (IS_ERR(pb->pwm)) {
dev_err(&pdev->dev, "unable to request legacy PWM\n");
@@ -339,6 +340,8 @@ static int pwm_backlight_remove(struct platform_device *pdev)
if (pb->exit)
pb->exit(&pdev->dev);
+ if (pb->legacy)
+ pwm_free(pb->pwm);
return 0;
}