linux-kernel - Re: [PATCH] drm/panel: himax-hx83112a: transition to mipi

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: <ZuI1L8mypd0kyw7V@embed-PC.myguest.virtualbox.org>
Date: Thu, 12 Sep 2024 05:56:23 +0530
From: Abhishek Tamboli <abhishektamboli9@...il.com>
To: Doug Anderson <dianders@...omium.org>
Cc: tejasvipin76@...il.com, neil.armstrong@...aro.org,
	quic_jesszhan@...cinc.com, maarten.lankhorst@...ux.intel.com,
	mripard@...nel.org, tzimmermann@...e.de, airlied@...il.com,
	daniel@...ll.ch, dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org, javierm@...hat.com
Subject: Re: [PATCH] drm/panel: himax-hx83112a: transition to mipi_dsi
 wrapped functions

On Tue, Sep 10, 2024 at 02:19:53PM -0700, Doug Anderson wrote:
> Hi,
> 
> On Sat, Sep 7, 2024 at 1:32 AM Tejas Vipin <tejasvipin76@...il.com> wrote:
> >
> > On 9/7/24 3:53 AM, Jessica Zhang wrote:
> > >
> > >
> > > On 9/6/2024 3:14 PM, Jessica Zhang wrote:
> > >>
> > >>
> > >> On 9/4/2024 7:15 AM, Tejas Vipin wrote:
> > >>> Changes the himax-hx83112a panel to use multi style functions for
> > >>> improved error handling.
> > >>>
> > >>> Signed-off-by: Tejas Vipin <tejasvipin76@...il.com>
> > >>
> > >> Reviewed-by: Jessica Zhang <quic_jesszhan@...cinc.com>
> > >
> > > Hi Tejas,
> > >
> > > Just a heads up, it seems that this might be a duplicate of this change [1]?
> > >
> > > Thanks,
> > >
> > > Jessica Zhang
> > >
> > > [1] https://patchwork.freedesktop.org/patch/612367/?series=138155&rev=1
> >
> > Ah, thanks for letting me know. I hadn't realized someone else had
> > started working on this too.
> >
> > However, I would argue that my patch [2] is a better candidate for merging
> > because of the following reasons:
> >
> > 1) Removes unnecessary error printing:
> > The mipi_dsi_*_multi() functions all have inbuilt error printing which
> > makes printing errors after hx83112a_on unnecessary as is addressed in
> > [2] like so:
> >
> > > -     ret = hx83112a_on(ctx);
> > > +     ret = hx83112a_on(ctx->dsi);
> > >       if (ret < 0) {
> > > -             dev_err(dev, "Failed to initialize panel: %d\n", ret);
> > >               gpiod_set_value_cansleep(ctx->reset_gpio, 1);
> > >               regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> > > -             return ret;
> > >       }
> >
> > [2] also removes the unnecessary dev_err after regulator_bulk_enable as was
> > addressed in [3] like so:
> >
> > >       ret = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> > > -     if (ret < 0) {
> > > -             dev_err(dev, "Failed to enable regulators: %d\n", ret);
> > > +     if (ret < 0)
> > >               return ret;
> > > -     }
> >
> > 2) Better formatting
> >
> > The mipi_dsi_dcs_write_seq_multi statements in [1] aren't formatted
> > quite right according to what has been done so far. They are written as
> > such in [1]:
> >
> > > +     mipi_dsi_dcs_write_seq_multi(&dsi_ctx, HX83112A_SETTP1,
> > >                              0x02, 0x00, 0xa8, 0x01, 0xa8, 0x0d, 0xa4, 0x0e);
> >
> > Where they should be written as such in [2]:
> >
> > > +     mipi_dsi_dcs_write_seq_multi(&dsi_ctx, HX83112A_SETTP1,
> > > +                                  0x02, 0x00, 0xa8, 0x01, 0xa8, 0x0d, 0xa4, 0x0e);
> >
> > All in all, the module generated using my patch ends up being a teensy
> > bit smaller (1% smaller). But if chronology is what is important, then
> > it would at least be nice to see the above changes as part of Abhishek's
> > patch too. And I'll be sure to look at the mail in the drm inbox now
> > onwards :p
> >
> > [1] https://patchwork.freedesktop.org/patch/612367/?series=138155&rev=1
> > [2] https://lore.kernel.org/all/20240904141521.554451-1-tejasvipin76@gmail.com/
> > [3] https://lore.kernel.org/all/CAD=FV=XRZKL_ppjUKDK61fQkWhHiQCJLfmVBS7wSo4sUux2g8Q@mail.gmail.com/
> 
> I would tend to agree that Tejas's patch looks slightly better, but
> Abhishek's patch appears to have been posted first.
> 
> Neil: any idea what to do here? Maybe a Co-Developed-by or something?
> ...or we could land Abhishek and Tejas could post a followup for the
> extra cleanup?
> 
> Abhishek: are you planning to post more _multi cleanups? 
I’ve just started learning about the DRM subsystem, I don’t have specific 
plans for _multi cleanups at the moment. However, I would be happy 
to contribute further.
>If so, please
> make sure to CC Tejas (who has been posting a bunch of them) and
> perhaps me since I've been helping to review them a bit.
Yes, I’ll make sure to CC Tejas and you.

Regards,
ABhishek