| Message ID | cbae7617db83113de726fcc423a805ebaa1bfca6.1680433978.git.hns@goldelico.com |
|---|---|
| State | New |
| Headers | show |
| Series | leds: tca6507: fix error handling of using fwnode_property_read_string | expand |
On Sun 2023-04-02 13:12:59, H. Nikolaus Schaller wrote: > Commit 96f524105b9c ("leds: tca6507: use fwnode API instead of OF") > > changed to fwnode API but did not take into account that a missing property > "linux,default-trigger" now seems to return an error and as a side effect > sets value to -1. This seems to be different from of_get_property() which > always returned NULL in any case of error. > > Neglecting this side-effect leads to > > [ 11.201965] Unable to handle kernel paging request at virtual address ffffffff when read > > in the strcmp() of led_trigger_set_default() if there is no led-trigger > defined in the DTS. > > I don't know if this was recently introduced somewhere in the fwnode lib > or if the effect was missed in initial testing. Anyways it seems to be a > bug to ignore the error return value of an optional value here in the > driver. > > Fixes: 96f524105b9c ("leds: tca6507: use fwnode API instead of OF") > Cc: Marek Behún <kabel@kernel.org> > Cc: NeilBrown <neilb@suse.de> > Cc: Linus Walleij <linus.walleij@linaro.org> > Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com> Acked-by: Pavel Machek <pavel@ucw.cz> BR, Pavel
On Sun, 02 Apr 2023, H. Nikolaus Schaller wrote: > Commit 96f524105b9c ("leds: tca6507: use fwnode API instead of OF") > > changed to fwnode API but did not take into account that a missing property > "linux,default-trigger" now seems to return an error and as a side effect > sets value to -1. This seems to be different from of_get_property() which > always returned NULL in any case of error. > > Neglecting this side-effect leads to > > [ 11.201965] Unable to handle kernel paging request at virtual address ffffffff when read > > in the strcmp() of led_trigger_set_default() if there is no led-trigger > defined in the DTS. > > I don't know if this was recently introduced somewhere in the fwnode lib > or if the effect was missed in initial testing. Anyways it seems to be a > bug to ignore the error return value of an optional value here in the > driver. > > Fixes: 96f524105b9c ("leds: tca6507: use fwnode API instead of OF") > Cc: Marek Behún <kabel@kernel.org> > Cc: NeilBrown <neilb@suse.de> > Cc: Linus Walleij <linus.walleij@linaro.org> > Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com> > --- > drivers/leds/leds-tca6507.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) Applied, thanks -- Lee Jones [李琼斯]
diff --git a/drivers/leds/leds-tca6507.c b/drivers/leds/leds-tca6507.c index 07dd12686a696..634cabd5bb796 100644 --- a/drivers/leds/leds-tca6507.c +++ b/drivers/leds/leds-tca6507.c @@ -691,8 +691,9 @@ tca6507_led_dt_init(struct device *dev) if (fwnode_property_read_string(child, "label", &led.name)) led.name = fwnode_get_name(child); - fwnode_property_read_string(child, "linux,default-trigger", - &led.default_trigger); + if (fwnode_property_read_string(child, "linux,default-trigger", + &led.default_trigger)) + led.default_trigger = NULL; led.flags = 0; if (fwnode_device_is_compatible(child, "gpio"))
Commit 96f524105b9c ("leds: tca6507: use fwnode API instead of OF") changed to fwnode API but did not take into account that a missing property "linux,default-trigger" now seems to return an error and as a side effect sets value to -1. This seems to be different from of_get_property() which always returned NULL in any case of error. Neglecting this side-effect leads to [ 11.201965] Unable to handle kernel paging request at virtual address ffffffff when read in the strcmp() of led_trigger_set_default() if there is no led-trigger defined in the DTS. I don't know if this was recently introduced somewhere in the fwnode lib or if the effect was missed in initial testing. Anyways it seems to be a bug to ignore the error return value of an optional value here in the driver. Fixes: 96f524105b9c ("leds: tca6507: use fwnode API instead of OF") Cc: Marek Behún <kabel@kernel.org> Cc: NeilBrown <neilb@suse.de> Cc: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com> --- drivers/leds/leds-tca6507.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)