Re: [PATCH v2] drm/dp: move intel_dp_vsc_sdp_pack() to generic helper

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Tue, Feb 20, 2024 at 11:27:18AM -0800, Abhinav Kumar wrote:
> 
> 
> On 2/20/2024 11:20 AM, Dmitry Baryshkov wrote:
> > On Tue, 20 Feb 2024 at 21:05, Dmitry Baryshkov
> > <dmitry.baryshkov@linaro.org> wrote:
> >>
> >> On Tue, 20 Feb 2024 at 20:53, Abhinav Kumar <quic_abhinavk@quicinc.com> wrote:
> >>>
> >>>
> >>>
> >>> On 2/20/2024 10:49 AM, Dmitry Baryshkov wrote:
> >>>> On Thu, 15 Feb 2024 at 21:08, Abhinav Kumar <quic_abhinavk@quicinc.com> wrote:
> >>>>>
> >>>>> intel_dp_vsc_sdp_pack() can be re-used by other DRM drivers as well.
> >>>>> Lets move this to drm_dp_helper to achieve this.
> >>>>>
> >>>>> changes in v2:
> >>>>>           - rebased on top of drm-tip
> >>>>>
> >>>>> Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> >>>>
> >>>> v1 had an explicit comment before the ack:
> >>>>
> >>>
> >>> Yes, I remember the comment. I did not make any changes to v2 other than
> >>> just rebasing it on drm-tip to get the ack from i915 folks.
> >>>
> >>>>>      From my side, with the promise of the size fixup.
> >>>>
> >>>> However I observe neither a second patch removing the size argument
> >>>> nor it being dropped as a part of this patch.
> >>>>
> >>>
> >>> Yes, now that in v2 we got the ack for this patch, I can spin a v3 with
> >>> the addition of the next patch to remove the size OR as another series
> >>> so as to not block the main series which needs this patch.
> >>>
> >>> I would prefer the latter.
> >>
> >> It doesn't work this way. The comment should have been fixed for v2.
> > 
> > This probably deserves some explanation. Currently there is only one
> > user of this function. So it is easy to fix it. Once there are several
> > users, you have to fix all of them at the same time, patching
> > different drm subtrees. That complicates the life of maintainers.
> > 
> 
> Yes, understood. Its easier to fix it now if its really needed.
> 
> Actually, I think the reason the size was passed was to make sure
> a valid struct dp_sdp *sdp was being passed.

The size is supposed to be the size of *hardware* buffer where this
gets written into. But looks like this wasn't done correctly when
the code was copy-pasted from the HDMI inforframe code.

-- 
Ville Syrjälä
Intel