linux-kernel - Re: [PATCH v2] drm/dp: move intel_dp_vsc_sdp

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ZdUAZZIO5Zk2Y8Wm@intel.com>
Date: Tue, 20 Feb 2024 21:41:25 +0200
From: Ville Syrjälä <ville.syrjala@...ux.intel.com>
To: Abhinav Kumar <quic_abhinavk@...cinc.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
	dri-devel@...ts.freedesktop.org,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>, Daniel Vetter <daniel@...ll.ch>,
	Jani Nikula <jani.nikula@...ux.intel.com>,
	Rodrigo Vivi <rodrigo.vivi@...el.com>,
	Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
	Tvrtko Ursulin <tvrtko.ursulin@...ux.intel.com>,
	robdclark@...il.com, freedreno@...ts.freedesktop.org,
	intel-gfx@...ts.freedesktop.org, quic_jesszhan@...cinc.com,
	linux-kernel@...r.kernel.org, intel-xe@...ts.freedesktop.org
Subject: Re: [PATCH v2] drm/dp: move intel_dp_vsc_sdp_pack() to generic helper

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@...aro.org> wrote:
> >>
> >> On Tue, 20 Feb 2024 at 20:53, Abhinav Kumar <quic_abhinavk@...cinc.com> wrote:
> >>>
> >>>
> >>>
> >>> On 2/20/2024 10:49 AM, Dmitry Baryshkov wrote:
> >>>> On Thu, 15 Feb 2024 at 21:08, Abhinav Kumar <quic_abhinavk@...cinc.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@...aro.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