[0/1] pwm-regulator: reduce noise on EPROBE_DEFER

Message

Martin Blumenstingl Jan. 21, 2019, 6:37 p.m. UTC

pwm-regulator can be a bit noisy during boot.

One example are the 32-bit Amlogic SoCs when using
multi_v7_defconfig (which has CONFIG_REGULATOR_PWM=y and
CONFIG_PWM_MESON=m). During boot the pwm-regulator is probed multiple
times - the first five tries end with EPROBE_DEFER. This is expected
because the pwm-meson driver is only loaded once rootfs is ready (as
it's compiled as kernel module).

Other drivers typically suppress an error message for EPROBE_DEFER
cases, so let's do the same for the pwm-regulator driver.

Example boot log where multiple "pwm-regulator regulator-vcck: Failed
to get PWM: -517" messages are logged (Odroid-C1, v5.0-rc3): [0]


[0] https://storage.kernelci.org/mainline/master/v5.0-rc3/arm/multi_v7_defconfig/lab-baylibre/boot-meson8b-odroidc1.html


Martin Blumenstingl (1):
  regulator: pwm: suppress EPROBE_DEFER error message

 drivers/regulator/pwm-regulator.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Mark Brown Jan. 21, 2019, 7:18 p.m. UTC | #1

On Mon, Jan 21, 2019 at 07:37:22PM +0100, Martin Blumenstingl wrote:
> pwm-regulator can be a bit noisy during boot.
> 
> One example are the 32-bit Amlogic SoCs when using
> multi_v7_defconfig (which has CONFIG_REGULATOR_PWM=y and

Please don't send cover letters for single patches, if there is anything
that needs saying put it in the changelog of the patch or after the ---
if it's administrative stuff.  This reduces mail volume and ensures that 
any important information is recorded in the changelog rather than being
lost.

Martin Blumenstingl Jan. 21, 2019, 8:55 p.m. UTC | #2

Hi Mark,

On Mon, Jan 21, 2019 at 8:18 PM Mark Brown <[e-mail]> wrote:
>
> On Mon, Jan 21, 2019 at 07:37:22PM +0100, Martin Blumenstingl wrote:
> > pwm-regulator can be a bit noisy during boot.
> >
> > One example are the 32-bit Amlogic SoCs when using
> > multi_v7_defconfig (which has CONFIG_REGULATOR_PWM=y and
>
> Please don't send cover letters for single patches, if there is anything
> that needs saying put it in the changelog of the patch or after the ---
> if it's administrative stuff.  This reduces mail volume and ensures that
> any important information is recorded in the changelog rather than being
> lost.
noted - sorry for the noise.

the patch description already contains all relevant information, so I
won't re-send the patch.
only the KernelCI link is not included because I'm not sure how long
it's valid (instead the description includes all relevant information
which also can be seen in the KernelCI link)


Regards
Martin