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References: <20210509044330.4655-1-pauldzim@gmail.com> <02957632-b050-f9eb-fcd8-75db9c92b8e0@ubuntu.com>
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From:   Paul Zimmerman <pauldzim@gmail.com>
Date:   Mon, 10 May 2021 13:49:42 -0700
Message-ID: <CADBGO7_cH2e1-zgVNvwVPRogqeFjTfJhKcuTfdF=xc_GoMmknA@mail.gmail.com>
Subject: Re: [Intel-gfx] [PATCH RFC] Revert "drm/i915: Try to use fast+narrow
 link on eDP again and fall back to the old max strategy on failure"
To:     Timo Aaltonen <tjaalton@ubuntu.com>
Cc:     Jani Nikula <jani.nikula@linux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@intel.com>,
        intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org
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On Mon, May 10, 2021 at 7:00 AM Timo Aaltonen <tjaalton@ubuntu.com> wrote:
>
> On 9.5.2021 7.43, Paul Zimmerman wrote:
> > This reverts commit 2bbd6dba84d44219387df051a1c799b7bac46099.
> >
> > Since 5.12-rc2, my Dell XPS-15 laptop has had a blank screen on boot.
> > The system seems to run fine other than having no display, I am able
> > to ssh into the machine. I don't see anything interesting in the dmesg
> > log. I bisected the problem down to this commit, and reverting it fixes
> > the problem.
>
> Have you tried with drm-tip? It has acca7762eb71bc0 which hopefully
> helps here.

I picked that one commit from the drm-tip tree (wasn't sure how to merge
the entire tree into the kernel) and can confirm that it does fix the problem.
Thank you! I hope the fix will be sent to Linus pretty soon, and it will need
backporting to the 5.12 kernel as well.

- Paul