| Message ID | 1449738546-10279-1-git-send-email-p.zabel@pengutronix.de |
|---|---|
| State | Not Applicable |
| Headers | show |
Philipp Zabel <p.zabel@pengutronix.de> writes: > Commit ee65ad0e2a9e ("backlight: pwm_bl: Avoid backlight flicker when > probed from DT") tries to dereference the device of_node pointer > unconditionally, causing a NULL pointer dereference on non-dt platforms. > Fix it by replacing the phandle variable with a node variable and > by checking that for NULL before dereferencing it. > > Reported-by: Robert Jarzmik <robert.jarzmik@free.fr> > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> And indeed it does the trick. Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
On Thu, Dec 10, 2015 at 10:09:06AM +0100, Philipp Zabel wrote: > Commit ee65ad0e2a9e ("backlight: pwm_bl: Avoid backlight flicker when > probed from DT") tries to dereference the device of_node pointer > unconditionally, causing a NULL pointer dereference on non-dt platforms. > Fix it by replacing the phandle variable with a node variable and > by checking that for NULL before dereferencing it. > > Reported-by: Robert Jarzmik <robert.jarzmik@free.fr> > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> > --- > drivers/video/backlight/pwm_bl.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) Acked-by: Thierry Reding <thierry.reding@gmail.com>
On Thu, 10 Dec 2015, Philipp Zabel wrote: > Commit ee65ad0e2a9e ("backlight: pwm_bl: Avoid backlight flicker when > probed from DT") tries to dereference the device of_node pointer > unconditionally, causing a NULL pointer dereference on non-dt platforms. > Fix it by replacing the phandle variable with a node variable and > by checking that for NULL before dereferencing it. > > Reported-by: Robert Jarzmik <robert.jarzmik@free.fr> > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> > --- > drivers/video/backlight/pwm_bl.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) Applied, thanks. > diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c > index 3daf9cc..a22c1ec 100644 > --- a/drivers/video/backlight/pwm_bl.c > +++ b/drivers/video/backlight/pwm_bl.c > @@ -198,8 +198,8 @@ static int pwm_backlight_probe(struct platform_device *pdev) > struct platform_pwm_backlight_data defdata; > struct backlight_properties props; > struct backlight_device *bl; > + struct device_node *node = pdev->dev.of_node; > struct pwm_bl_data *pb; > - phandle phandle = pdev->dev.of_node->phandle; > int initial_blank = FB_BLANK_UNBLANK; > int ret; > > @@ -273,7 +273,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) > * assume that another driver will enable the backlight at the > * appropriate time. Therefore, if it is disabled, keep it so. > */ > - if (phandle && > + if (node && node->phandle && > gpiod_get_direction(pb->enable_gpio) == GPIOF_DIR_OUT && > gpiod_get_value(pb->enable_gpio) == 0) > initial_blank = FB_BLANK_POWERDOWN; > @@ -287,12 +287,11 @@ static int pwm_backlight_probe(struct platform_device *pdev) > goto err_alloc; > } > > - if (phandle && !regulator_is_enabled(pb->power_supply)) > + if (node && node->phandle && !regulator_is_enabled(pb->power_supply)) > initial_blank = FB_BLANK_POWERDOWN; > > pb->pwm = devm_pwm_get(&pdev->dev, NULL); > - if (IS_ERR(pb->pwm) && PTR_ERR(pb->pwm) != -EPROBE_DEFER > - && !pdev->dev.of_node) { > + if (IS_ERR(pb->pwm) && PTR_ERR(pb->pwm) != -EPROBE_DEFER && !node) { > dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n"); > pb->legacy = true; > pb->pwm = pwm_request(data->pwm_id, "pwm-backlight");
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 3daf9cc..a22c1ec 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -198,8 +198,8 @@ static int pwm_backlight_probe(struct platform_device *pdev) struct platform_pwm_backlight_data defdata; struct backlight_properties props; struct backlight_device *bl; + struct device_node *node = pdev->dev.of_node; struct pwm_bl_data *pb; - phandle phandle = pdev->dev.of_node->phandle; int initial_blank = FB_BLANK_UNBLANK; int ret; @@ -273,7 +273,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) * assume that another driver will enable the backlight at the * appropriate time. Therefore, if it is disabled, keep it so. */ - if (phandle && + if (node && node->phandle && gpiod_get_direction(pb->enable_gpio) == GPIOF_DIR_OUT && gpiod_get_value(pb->enable_gpio) == 0) initial_blank = FB_BLANK_POWERDOWN; @@ -287,12 +287,11 @@ static int pwm_backlight_probe(struct platform_device *pdev) goto err_alloc; } - if (phandle && !regulator_is_enabled(pb->power_supply)) + if (node && node->phandle && !regulator_is_enabled(pb->power_supply)) initial_blank = FB_BLANK_POWERDOWN; pb->pwm = devm_pwm_get(&pdev->dev, NULL); - if (IS_ERR(pb->pwm) && PTR_ERR(pb->pwm) != -EPROBE_DEFER - && !pdev->dev.of_node) { + if (IS_ERR(pb->pwm) && PTR_ERR(pb->pwm) != -EPROBE_DEFER && !node) { dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n"); pb->legacy = true; pb->pwm = pwm_request(data->pwm_id, "pwm-backlight");
Commit ee65ad0e2a9e ("backlight: pwm_bl: Avoid backlight flicker when probed from DT") tries to dereference the device of_node pointer unconditionally, causing a NULL pointer dereference on non-dt platforms. Fix it by replacing the phandle variable with a node variable and by checking that for NULL before dereferencing it. Reported-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> --- drivers/video/backlight/pwm_bl.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)