# \[PATCH\] pwm-backlight: fix probing from device-tree without enable-gpios - Subsystems: FRAMEBUFFER LAYER, BACKLIGHT CLASS/SUBSYSTEM, THE REST - Maintainers: Helge Deller, Lee Jones, Daniel Thompson, Jingoo Han, Linus Torvalds - List: linux-fbdev - 3 messages, 2 authors - Page: https://ratatoskr.run/linux-fbdev/2014/07/4303421/t ## \[PATCH\] pwm-backlight: fix probing from device-tree without enable-gpios - From: Michael Olbrich \ - Date: 2014-07-25 10:29:08 - Message: https://ratatoskr.run/linux-fbdev/2014/07/4303421.md ```text Since 257462dbf3ed ("pwm-backlight: switch to gpiod interface") enable_gpio is no longer set and remains 0 when probing from device-tree. This is a valid gpio number. With no enable-gpios specified in the device-tree this is used and probing fails with: pwm-backlight lcd-backlight.3: failed to request GPIO#0: -16 Fix this by setting enable_gpio to -1 which is not a valid gpio number. Signed-off-by: Michael Olbrich --- drivers/video/backlight/pwm_bl.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 38ca88b..5213d13 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -211,6 +211,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) dev_err(&pdev->dev, "failed to find platform data\n"); return ret; } + devdata.enable_gpio = -1; data = &defdata; } -- 2.0.1 ``` ## \[PATCH v2\] pwm-backlight: fix probing from device-tree without enable-gpios - From: Michael Olbrich \ - Date: 2014-07-25 11:48:14 - Message: https://ratatoskr.run/linux-fbdev/2014/07/4303467.md ```text Since 257462dbf3ed ("pwm-backlight: switch to gpiod interface") enable_gpio is no longer set and remains 0 when probing from device-tree. This is a valid gpio number. With no enable-gpios specified in the device-tree this is used and probing fails with: pwm-backlight lcd-backlight.3: failed to request GPIO#0: -16 Fix this by setting enable_gpio to -1 which is not a valid gpio number. Signed-off-by: Michael Olbrich --- Sorry, I sent the wrong version. This one actually compiles. Michael drivers/video/backlight/pwm_bl.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 38ca88b..e7e43cd 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -211,6 +211,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) dev_err(&pdev->dev, "failed to find platform data\n"); return ret; } + defdata.enable_gpio = -1; data = &defdata; } -- 2.0.1 ``` ## Re: \[PATCH v2\] pwm-backlight: fix probing from device-tree without enable-gpios - From: Alexandre Courbot \ - Date: 2014-07-25 14:47:16 - Message: https://ratatoskr.run/linux-fbdev/2014/07/4303588.md ```text On Fri, Jul 25, 2014 at 8:47 PM, Michael Olbrich [ref] wrote: > Since 257462dbf3ed ("pwm-backlight: switch to gpiod interface") > enable_gpio is no longer set and remains 0 when probing from > device-tree. This is a valid gpio number. With no enable-gpios > specified in the device-tree this is used and probing fails > with: > > pwm-backlight lcd-backlight.3: failed to request GPIO#0: -16 > > Fix this by setting enable_gpio to -1 which is not a valid gpio > number. Looks good indeed. My bad for overlooking this. Acked-by: Alexandre Courbot > > Signed-off-by: Michael Olbrich > --- > > Sorry, I sent the wrong version. This one actually compiles. > > Michael > > drivers/video/backlight/pwm_bl.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c > index 38ca88b..e7e43cd 100644 > --- a/drivers/video/backlight/pwm_bl.c > +++ b/drivers/video/backlight/pwm_bl.c > @@ -211,6 +211,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) > dev_err(&pdev->dev, "failed to find platform data\n"); > return ret; > } > + defdata.enable_gpio = -1; > > data = &defdata; > } > -- > 2.0.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html ```