Hi Uwe, On Wed, 7 Nov 2018 at 17:29, Uwe Kleine-König <[email protected]> wrote: > > Hello, > > On Wed, Nov 07, 2018 at 10:36:13AM +0100, Clément Péron wrote: > > From: Suji Velupillai <[email protected]> > > > > When pwm_bl framework calls enable, a call to pwm_is_enabled(pwm) still > > return false, this prevents the backlight being turn on at boot time. > > > > Signed-off-by: Suji Velupillai <[email protected]> > > Signed-off-by: Clément Péron <[email protected]> > > --- > > drivers/pwm/pwm-bcm-kona.c | 16 +++++++++++----- > > 1 file changed, 11 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c > > index 09a95aeb3a70..d991d53c4b38 100644 > > --- a/drivers/pwm/pwm-bcm-kona.c > > +++ b/drivers/pwm/pwm-bcm-kona.c > > @@ -108,8 +108,8 @@ static void kona_pwmc_apply_settings(struct kona_pwmc > > *kp, unsigned int chan) > > ndelay(400); > > } > > > > -static int kona_pwmc_config(struct pwm_chip *chip, struct pwm_device *pwm, > > - int duty_ns, int period_ns) > > +static int __pwmc_config(struct pwm_chip *chip, struct pwm_device *pwm, > > + int duty_ns, int period_ns, bool pwmc_enabled) > > { > > struct kona_pwmc *kp = to_kona_pwmc(chip); > > u64 val, div, rate; > > @@ -155,7 +155,7 @@ static int kona_pwmc_config(struct pwm_chip *chip, > > struct pwm_device *pwm, > > * always calculated above to ensure the new values are > > * validated immediately instead of on enable. > > */ > > - if (pwm_is_enabled(pwm)) { > > + if (pwm_is_enabled(pwm) || pwmc_enabled) { > > Having pwm-API-calls in hw-drivers is ugly. Apart from not giving the > intended return code this function should IMHO be reserved to pwm > consumers. The underlaying problem is that pwm-bl does: > > pwm_config(pwm, duty_cycle, period); > pwm_enable(pwm); > > and expects that the duty_cycle and period is used then. Doesn't > everything works just fine if the if-block is always executed?
Tested and works fine for me. But I only have a Cygnus proc. Maybe there is some issue with Kona as explained by the comment (even if I don't understand it well). * Don't apply settings if disabled. The period and duty cycle are * always calculated above to ensure the new values are * validated immediately instead of on enable. Regards, Clement > > The better fix here would be to convert the driver to the atomic API > (i.e. implement .apply instead of .config, .set_polarity, .enable and > .disable). > > Alternatively in .enable ensure that the hardware is programmed with the > parameters from pwm->state. (But converting to the atomic API is the > better approach.) > > Best regards > Uwe > > -- > Pengutronix e.K. | Uwe Kleine-König | > Industrial Linux Solutions | http://www.pengutronix.de/ |
