On Wed, 08 Feb 2017, "Shankar, Uma" <uma.shankar@xxxxxxxxx> wrote: >>-----Original Message----- >>From: Intel-gfx [mailto:intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx] On Behalf Of >>Jani Nikula >>Sent: Wednesday, February 8, 2017 4:41 PM >>To: Srinivas, Vidya <vidya.srinivas@xxxxxxxxx>; intel- >>gfx@xxxxxxxxxxxxxxxxxxxxx >>Subject: Re: [PATCH 01/14] drm/i915: Check for platform specific >>GPIO config >> >>On Wed, 08 Feb 2017, "Srinivas, Vidya" <vidya.srinivas@xxxxxxxxx> wrote: >>>> -----Original Message----- >>>> From: Jani Nikula [mailto:jani.nikula@xxxxxxxxxxxxxxx] >>>> Sent: Wednesday, February 8, 2017 4:11 PM >>>> To: Srinivas, Vidya <vidya.srinivas@xxxxxxxxx>; intel- >>>> gfx@xxxxxxxxxxxxxxxxxxxxx >>>> Subject: RE: [PATCH 01/14] drm/i915: Check for platform >>>> specific GPIO config >>>> >>>> On Wed, 08 Feb 2017, "Srinivas, Vidya" <vidya.srinivas@xxxxxxxxx> wrote: >>>> >> -----Original Message----- >>>> >> From: Jani Nikula [mailto:jani.nikula@xxxxxxxxxxxxxxx] >>>> >> Sent: Monday, January 9, 2017 3:48 PM >>>> >> To: Srinivas, Vidya <vidya.srinivas@xxxxxxxxx>; intel- >>>> >> gfx@xxxxxxxxxxxxxxxxxxxxx >>>> >> Subject: Re: [PATCH 01/14] drm/i915: Check for >>>> >> platform specific GPIO config >>>> >> >>>> >> On Mon, 09 Jan 2017, Vidya Srinivas <vidya.srinivas@xxxxxxxxx> wrote: >>>> >> > From: Uma Shankar <uma.shankar@xxxxxxxxx> >>>> >> > >>>> >> > Panel GPIO control should be done based on platform. Add a check >>>> >> > to restrict VLV and CHT specific GPIO confirguration, so that >>>> >> > they dont apply to other platforms. >>>> >> >>>> >> There are no code paths that would have >>>> >> dev_priv->vbt.dsi.config->pwm_blc == PPS_BLC_PMIC on platforms >>>> >> other than VLV/CVH. >>>> > This particular field is by default 0 which triggers a redundant >>>> > gpio get operation for BXT. Hence limiting this to BYT/CHT platforms. >>>> >>>> What do you mean by default 0? Are you saying that you have machines >>>> that have a VBT which indicate they have PMIC backlight control when >>>> they in fact don't? >>> >>> Sorry, what I meant is PPS_BLC_PMIC is 0. So even if the VBT field is >>> not changed it will still become true causing the condition to pass. >> >>In other words, the VBT contains PPS_BLC_PMIC for a machine that should >>not use PMIC. In yet other words, the VBT contains incorrect information. >>Right? >> > > Hi Jani, > In this case, I guess the design for this value itself is wrong. A value of 0 is a valid value > from driver/vbt perspective (basically signifies some logical entity). Thus if we don't touch this > field in VBT, it will still have 0 as a value (un-initialized). Driver will consider it to be right and will go > ahead with GPIO get calls. Ideally this should start from index as 1 or a default value of -1 was needed. > > In BYT/CHT, most platforms will be using that hence things were fine. If a board design needed other value, > VBT field would have been updated. But this is not at all needed for platforms beyond BYT/CHT, hence this > change was limited to those platforms. I filed a bug against the spec. That's where this info should be. BR, Jani. > > Regards, > Uma Shankar > >>BR, >>Jani. >> >> >>>> >>>> BR, >>>> Jani. >>>> >>>> >>>> >>>> > >>>> > Regards >>>> > Vidya >>>> >> >>>> >> BR, >>>> >> Jani. >>>> >> >>>> >> > >>>> >> > Signed-off-by: Uma Shankar <uma.shankar@xxxxxxxxx> >>>> >> > --- >>>> >> > drivers/gpu/drm/i915/intel_dsi.c | 3 ++- >>>> >> > 1 file changed, 2 insertions(+), 1 deletion(-) >>>> >> > >>>> >> > diff --git a/drivers/gpu/drm/i915/intel_dsi.c >>>> >> > b/drivers/gpu/drm/i915/intel_dsi.c >>>> >> > index 16732e7..27d8f95 100644 >>>> >> > --- a/drivers/gpu/drm/i915/intel_dsi.c >>>> >> > +++ b/drivers/gpu/drm/i915/intel_dsi.c >>>> >> > @@ -1560,7 +1560,8 @@ void intel_dsi_init(struct >>>> >> > drm_i915_private >>>> >> *dev_priv) >>>> >> > * In case of BYT with CRC PMIC, we need to use GPIO for >>>> >> > * Panel control. >>>> >> > */ >>>> >> > - if (dev_priv->vbt.dsi.config->pwm_blc == PPS_BLC_PMIC) { >>>> >> > + if ((IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) >>&& >>>> >> > + (dev_priv->vbt.dsi.config->pwm_blc == >>PPS_BLC_PMIC)) { >>>> >> > intel_dsi->gpio_panel = >>>> >> > gpiod_get(dev->dev, "panel", >>GPIOD_OUT_HIGH); >>>> >> >>>> >> -- >>>> >> Jani Nikula, Intel Open Source Technology Center >>>> >>>> -- >>>> Jani Nikula, Intel Open Source Technology Center >> >>-- >>Jani Nikula, Intel Open Source Technology Center >>_______________________________________________ >>Intel-gfx mailing list >>Intel-gfx@xxxxxxxxxxxxxxxxxxxxx >>https://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
