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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Tue, 11 Sep 2018 10:17:27 +0200
Message-ID: <CAJZ5v0i3gH4H6Su5MPWA3DA_i4mvHEqfw3y=rr0XOpZi5bbqhA@mail.gmail.com>
Subject: Re: [REGRESSION 4.19-rc2] sometimes hangs with black screen when
 resuming from suspend or hibernation (was: Re: Linux 4.19-rc2)
To:     martin@lichtvoll.de
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Hi,

On Tue, Sep 11, 2018 at 10:01 AM Martin Steigerwald <martin@lichtvoll.de> wrote:
>
> Hi.
>
> Linus Torvalds - 02.09.18, 23:45:
> > As usual, the rc2 release is pretty small. People are taking a
>
> With 4.19-rc2 this ThinkPad T520 with i5 Sandybrdige sometimes hangs
> with black screen when resuming from suspend or hibernation.  With
> 4.18.1 it did not. Of course there have been userspace related updates
> that could be related.
>
> I currently have no time to dig into this and on this production laptop
> I generally do not do bisects between major kernel releases. So
> currently I only answer questions that do not require much time to
> answer.
>
> For now I switched back to 4.18. If that is stable – and thus likely no
> userspace component is related –, I go with 4.19-rc3 or whatever is most
> recent version to see if the issue has been fixed already.

There were almost no general changes related to system-wide PM between
4.18 and current, so I would suspect one of the device drivers or the
x86 core.  It also may be something like CPU online/offline, however.

Thanks,
Rafael