| Message ID | 20170717212811.25374-5-enric.balletbo@collabora.com |
|---|---|
| State | Superseded |
| Headers | show |
On Mon 2017-07-17 23:28:11, Enric Balletbo i Serra wrote: > The minnie devices comes with an AUO B101EAN01 panel which is different > from default veyron devices, thus the power on/off timing sequence is > slightly different. The datasheet specifies a pwm delay of 200 ms, so > update the PMW delay proprieties accordingly. Wait a wait a moment! > --- a/arch/arm/boot/dts/rk3288-veyron-minnie.dts > +++ b/arch/arm/boot/dts/rk3288-veyron-minnie.dts > @@ -123,6 +123,8 @@ > 240 241 242 243 244 245 246 247 > 248 249 250 251 252 253 254 255>; > power-supply = <&backlight_regulator>; > + post-pwm-on-delay-us = <20000>; -us = <20 000>; This is not 200 msec. Plus, it is quite anti-social to do udelay(200 000). Plus, it is very anti-socifal to use udelay_range(200msec, 400msec). Whoever told you udelay_range is good thing to use -- it is not, and it is certainly not worth making user wait 200msec more! Pavel
Pavel, 2017-07-20 10:10 GMT+02:00 Pavel Machek <pavel@ucw.cz>: > On Mon 2017-07-17 23:28:11, Enric Balletbo i Serra wrote: >> The minnie devices comes with an AUO B101EAN01 panel which is different >> from default veyron devices, thus the power on/off timing sequence is >> slightly different. The datasheet specifies a pwm delay of 200 ms, so >> update the PMW delay proprieties accordingly. > > Wait a wait a moment! > >> --- a/arch/arm/boot/dts/rk3288-veyron-minnie.dts >> +++ b/arch/arm/boot/dts/rk3288-veyron-minnie.dts >> @@ -123,6 +123,8 @@ >> 240 241 242 243 244 245 246 247 >> 248 249 250 251 252 253 254 255>; >> power-supply = <&backlight_regulator>; >> + post-pwm-on-delay-us = <20000>; > > -us = <20 000>; > > This is not 200 msec. > Oops, good catch. > Plus, it is quite anti-social to do udelay(200 000). > > Plus, it is very anti-socifal to use udelay_range(200msec, > 400msec). > > Whoever told you udelay_range is good thing to use -- it is not, and > it is certainly not worth making user wait 200msec more! > Checked again some datasheets and seems that or not require a delay or the delays are 10ms+, so according to [1] I'll use msleep instead. [1] https://www.kernel.org/doc/Documentation/timers/timers-howto.txt Thanks, Enric > Pavel > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe linux-pwm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi! > 2017-07-20 10:10 GMT+02:00 Pavel Machek <pavel@ucw.cz>: > > On Mon 2017-07-17 23:28:11, Enric Balletbo i Serra wrote: > >> The minnie devices comes with an AUO B101EAN01 panel which is different > >> from default veyron devices, thus the power on/off timing sequence is > >> slightly different. The datasheet specifies a pwm delay of 200 ms, so > >> update the PMW delay proprieties accordingly. > > > > Wait a wait a moment! > > > >> --- a/arch/arm/boot/dts/rk3288-veyron-minnie.dts > >> +++ b/arch/arm/boot/dts/rk3288-veyron-minnie.dts > >> @@ -123,6 +123,8 @@ > >> 240 241 242 243 244 245 246 247 > >> 248 249 250 251 252 253 254 255>; > >> power-supply = <&backlight_regulator>; > >> + post-pwm-on-delay-us = <20000>; > > > > -us = <20 000>; > > > > This is not 200 msec. > > > > Oops, good catch. > > > Plus, it is quite anti-social to do udelay(200 000). > > > > Plus, it is very anti-socifal to use udelay_range(200msec, > > 400msec). > > > > Whoever told you udelay_range is good thing to use -- it is not, and > > it is certainly not worth making user wait 200msec more! > > > > Checked again some datasheets and seems that or not require a delay or > the delays are 10ms+, so according to [1] I'll use msleep instead. > > [1] https://www.kernel.org/doc/Documentation/timers/timers-howto.txt Ok, msleep makes sense. But in such case, you probably want to specify delays in the miliseconds in the device tree... or at least carefully round the values up. Best regards, Pavel
diff --git a/arch/arm/boot/dts/rk3288-veyron-minnie.dts b/arch/arm/boot/dts/rk3288-veyron-minnie.dts index 544de60..a5b7387 100644 --- a/arch/arm/boot/dts/rk3288-veyron-minnie.dts +++ b/arch/arm/boot/dts/rk3288-veyron-minnie.dts @@ -123,6 +123,8 @@ 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255>; power-supply = <&backlight_regulator>; + post-pwm-on-delay-us = <20000>; + pwm-off-delay-us = <20000>; }; &emmc {
The minnie devices comes with an AUO B101EAN01 panel which is different from default veyron devices, thus the power on/off timing sequence is slightly different. The datasheet specifies a pwm delay of 200 ms, so update the PMW delay proprieties accordingly. Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> --- Heiko, I'm not able to test this patch in a minnie device because I don't have one, so could you do a quick try, please? Changes since v2: - Use new names for proprieties. Changes since v1: - Add this new patch as minnie has differents timings arch/arm/boot/dts/rk3288-veyron-minnie.dts | 2 ++ 1 file changed, 2 insertions(+)