Re: [PATCH v2] drm/msm/dp: enable widebus on all relevant chipsets

[Abhinav Kumar]

On 7/30/2024 4:34 PM, Dmitry Baryshkov wrote:
> On Wed, 31 Jul 2024 at 01:27, Bjorn Andersson <quic_bjorande@xxxxxxxxxxx> wrote:
> > On Tue, Jul 30, 2024 at 11:58:19PM +0300, Dmitry Baryshkov wrote:
> > > Hi Abhinav,
> > >
> > > On Tue, 30 Jul 2024 at 22:50, Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx> wrote:
> > > > Hardware document indicates that widebus is recommended on DP on all
> > > > MDSS chipsets starting version 5.x.x and above.
> > > >
> > > > Follow the guideline and mark widebus support on all relevant
> > > > chipsets for DP.
> > > >
> > > > Fixes: 766f705204a0 ("drm/msm/dp: Remove now unused connector_type from desc")
> > > > Fixes: 1b2d98bdd7b7 ("drm/msm/dp: Add DisplayPort controller for SM8650")
> > >
> > > The issues are present in the following commits. Please consider using
> > > them instead:
> > >
> > > Fixes: 757a2f36ab09 ("drm/msm/dp: enable widebus feature for display port")
> > > Fixes: 1b2d98bdd7b7 ("drm/msm/dp: Add DisplayPort controller for SM8650")
> >
> > But are we really fixing any bugs/issues here? While the docs do
> > recommend widebus, we're effectively enabling more harware/features.
> >
> > Unless there's a strong reason (which I'm not confident that the commit
> > message entails), I think we should drop the fixes-tags and just bring
> > this to 6.12...
>
> I'm fine either way. I'll check tomorrow if this is required to fix
> https://gitlab.freedesktop.org/drm/msm/-/issues/43.

In v1, I also did not have the Fixes tag and I admit, originally even 
though I made the change in an attempt to fix another issue, it was not 
resolving the issue completely so there is no functional issue getting 
fixed due to the change.

I have confirmed that on my setup this patch is not needed to fix that bug.

I decided to add the Fixes tag in v2 because not following the hw doc 
recommendation is also a bug as it can lead to unexplained issues. Thats 
why I am still divided on this.

If the consensus is not to take it as a fix, I am fine with it and will 
not include it and while we are compiling the changes for 6.12 this can 
be included without the Fixes tags.

>