linux-kernel - Re: [PATCH 6/8] fbdev: sm712fb: fix crashes and garbled display during DPMS modesetting.

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Date:   Sun, 31 Mar 2019 13:20:28 +0100
From:   Sudip Mukherjee <sudipm.mukherjee@...il.com>
To:     Yifeng Li <tomli@...li.me>
Cc:     Teddy Wang <teddy.wang@...iconmotion.com>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        linux-fbdev@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org, stable@...r.kernel.org
Subject: Re: [PATCH 6/8] fbdev: sm712fb: fix crashes and garbled display
 during DPMS modesetting.

On Sun, Mar 17, 2019 at 06:25:02AM +0800, Yifeng Li wrote:
> On a Thinkpad s30 (Pentium III / i440MX, Lynx3DM), blanking the display
> or starting the X server will crash and freeze the system, or garble the
> display.
> 
> Experiments showed this problem can mostly be solved by adjusting the
> order of register writes. Also, sm712fb failed to consider the difference
> of clock frequency when unblanking the display, and programs the clock for
> SM712 to SM720.
> 
> Fix them by adjusting the order of register writes, and adding an
> additional check for SM720 for programming the clock frequency.
> 
> Signed-off-by: Yifeng Li <tomli@...li.me>
> Cc: stable@...r.kernel.org  # v4.4+

Tested-by: Sudip Mukherjee <sudipm.mukherjee@...il.com>

--
Regards
Sudip