Re: [PATCH v2 4/4] drm/dp: fallback to maximum when PWM bit count is zero

[Dmitry Baryshkov]

On Wed, Mar 26, 2025 at 03:08:30PM +0000, Christopher Obbard wrote:
> Hi Dmitry,
> 
> On Tue, 25 Mar 2025 at 22:53, Dmitry Baryshkov
> <dmitry.baryshkov@xxxxxxxxxxxxxxxx> wrote:
> >
> > On 25/03/2025 21:21, Christopher Obbard wrote:
> > > Some eDP devices report DP_EDP_PWMGEN_BIT_COUNT as 0, but still provide
> > > valid non-zero MIN and MAX values. This patch reworks the logic to
> > > fallback to the max value in such cases, ensuring correct backlight PWM
> > > configuration even when the bit count value is not explicitly set.
> >
> > I don't think this matches the eDP standard. It tells to use MIN if
> > BIT_COUNT is less than MIN, if I understand it correctly.
> 
> Thanks for your comment; that's a good point.
> 
> I need to re-read this section of the spec; but at least on this
> hardware I printed the values of the registers and it seems like
> MIN and MAX are the same, so I could switch the patch around to use
> MIN in the next version.

SGTM.

-- 
With best wishes
Dmitry