[PATCH] leds: led-class: detect brightness conversion base from string

[PATCH] leds: led-class: detect brightness conversion base from string

[Michael Tretter]

From: Thorsten Schmelzer <tschmelzer@topcon.com>

sysfs-class-led doesn't specify the number format for the brightness,
but the class only accepts base 10 numbers.

Use the automatic base detection of kstrtoul and accept the brightness
as hex value as well.

Signed-off-by: Thorsten Schmelzer <tschmelzer@topcon.com>
Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
---
 drivers/leds/led-class.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index d34a19453560..8993b78b4162 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -55,7 +55,7 @@ static ssize_t brightness_store(struct device *dev,
 		goto unlock;
 	}
 
-	ret = kstrtoul(buf, 10, &state);
+	ret = kstrtoul(buf, 0, &state);
 	if (ret)
 		goto unlock;
 

---
base-commit: c072629f05d7bca1148ab17690d7922a31423984
change-id: 20260123-leds-class-convert-brightness-value-c46608002873

Best regards,
-- 
Michael Tretter <m.tretter@pengutronix.de>

Re: (subset) [PATCH] leds: led-class: detect brightness conversion base from string

[Lee Jones]

On Fri, 23 Jan 2026 10:57:26 +0100, Michael Tretter wrote:
> sysfs-class-led doesn't specify the number format for the brightness,
> but the class only accepts base 10 numbers.
> 
> Use the automatic base detection of kstrtoul and accept the brightness
> as hex value as well.
> 
> 
> [...]

Applied, thanks!

[1/1] leds: led-class: detect brightness conversion base from string
      commit: 07da045a49bd4cb17678d74efbdd600c71b136d4

--
Lee Jones [李琼斯]

Re: [PATCH] leds: led-class: detect brightness conversion base from string

[Andy Shevchenko]

On Fri, Jan 23, 2026 at 10:57:26AM +0100, Michael Tretter wrote:
> From: Thorsten Schmelzer <tschmelzer@topcon.com>
> 
> sysfs-class-led doesn't specify the number format for the brightness,
> but the class only accepts base 10 numbers.
> 
> Use the automatic base detection of kstrtoul and accept the brightness
> as hex value as well.

This obviously brings a regression.
Previously the 000000000000100 is 100, now it's 64.

While I don't care much (I even like the change), I have to point this out.

The correct fix is to update documentation.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH] leds: led-class: detect brightness conversion base from string

[Lee Jones]

On Thu, 05 Mar 2026, Andy Shevchenko wrote:

> On Fri, Jan 23, 2026 at 10:57:26AM +0100, Michael Tretter wrote:
> > From: Thorsten Schmelzer <tschmelzer@topcon.com>
> > 
> > sysfs-class-led doesn't specify the number format for the brightness,
> > but the class only accepts base 10 numbers.
> > 
> > Use the automatic base detection of kstrtoul and accept the brightness
> > as hex value as well.
> 
> This obviously brings a regression.
> Previously the 000000000000100 is 100, now it's 64.
> 
> While I don't care much (I even like the change), I have to point this out.
> 
> The correct fix is to update documentation.

Again, should we remove this patch that you like?

-- 
Lee Jones [李琼斯]

Re: [PATCH] leds: led-class: detect brightness conversion base from string

[Andy Shevchenko]

On Fri, Mar 06, 2026 at 11:32:21AM +0000, Lee Jones wrote:
> On Thu, 05 Mar 2026, Andy Shevchenko wrote:
> > On Fri, Jan 23, 2026 at 10:57:26AM +0100, Michael Tretter wrote:
> > > From: Thorsten Schmelzer <tschmelzer@topcon.com>
> > > 
> > > sysfs-class-led doesn't specify the number format for the brightness,
> > > but the class only accepts base 10 numbers.
> > > 
> > > Use the automatic base detection of kstrtoul and accept the brightness
> > > as hex value as well.
> > 
> > This obviously brings a regression.
> > Previously the 000000000000100 is 100, now it's 64.
> > 
> > While I don't care much (I even like the change), I have to point this out.
> > 
> > The correct fix is to update documentation.
> 
> Again, should we remove this patch that you like?

Depends if anybody outside relies on the above mentioned decimal values
with leading 0(s). On the safest side is better to drop (and explain in
the documentation that the values are decimal).

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH] leds: led-class: detect brightness conversion base from string

[Lee Jones]

On Fri, 06 Mar 2026, Andy Shevchenko wrote:

> On Fri, Mar 06, 2026 at 11:32:21AM +0000, Lee Jones wrote:
> > On Thu, 05 Mar 2026, Andy Shevchenko wrote:
> > > On Fri, Jan 23, 2026 at 10:57:26AM +0100, Michael Tretter wrote:
> > > > From: Thorsten Schmelzer <tschmelzer@topcon.com>
> > > > 
> > > > sysfs-class-led doesn't specify the number format for the brightness,
> > > > but the class only accepts base 10 numbers.
> > > > 
> > > > Use the automatic base detection of kstrtoul and accept the brightness
> > > > as hex value as well.
> > > 
> > > This obviously brings a regression.
> > > Previously the 000000000000100 is 100, now it's 64.
> > > 
> > > While I don't care much (I even like the change), I have to point this out.
> > > 
> > > The correct fix is to update documentation.
> > 
> > Again, should we remove this patch that you like?
> 
> Depends if anybody outside relies on the above mentioned decimal values
> with leading 0(s). On the safest side is better to drop (and explain in
> the documentation that the values are decimal).

For the fear of breaking userspace, I have dropped the patch.

Please could someone update the docs?

-- 
Lee Jones [李琼斯]

Re: [PATCH] leds: led-class: detect brightness conversion base from string

[Andy Shevchenko]

On Tue, Mar 10, 2026 at 09:23:19AM +0000, Lee Jones wrote:
> On Fri, 06 Mar 2026, Andy Shevchenko wrote:
> > On Fri, Mar 06, 2026 at 11:32:21AM +0000, Lee Jones wrote:
> > > On Thu, 05 Mar 2026, Andy Shevchenko wrote:
> > > > On Fri, Jan 23, 2026 at 10:57:26AM +0100, Michael Tretter wrote:

...

> > > > The correct fix is to update documentation.
> > > 
> > > Again, should we remove this patch that you like?
> > 
> > Depends if anybody outside relies on the above mentioned decimal values
> > with leading 0(s). On the safest side is better to drop (and explain in
> > the documentation that the values are decimal).
> 
> For the fear of breaking userspace, I have dropped the patch.
> 
> Please could someone update the docs?

Done in 20260310165143.354065-1-andriy.shevchenko@linux.intel.com.

-- 
With Best Regards,
Andy Shevchenko