From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Hellstrom <thellstrom@vmware.com>
Subject: Re: [PATCH 1/1] drm/vmwgfx: correct fb_fix_screeninfo.line_length
Date: Mon, 30 Jun 2014 15:03:02 +0200
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To: Christopher Friedt <chrisfriedt@gmail.com>
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On 06/30/2014 02:49 PM, Christopher Friedt wrote:
> On Mon, Jun 30, 2014 at 8:39 AM, Thomas Hellstrom <thellstrom@vmware.com> wrote:
>> xf86-video-vmware in kms mode uses the kernel driver to set these registers.
>> FWIW, the modesetting part of the kernel driver uses SVGA_REG_PITCHLOCK
>> instead of
>> SVGA_REG_BYTES_PER_LINE to set the pitch. That's probably where the
>> clash happens.
> That sounds a bit more accurate. Should kms and fbdev be setting both
> registers then?

>>From a quick browse of the device code, it looks like
SVGA_REG_BYTES_PER_LINE is intended for reading only, but I've asked the
experts that are on US time.

However, since the function
vmw_kms_write_svga()
should set up the pitch correctly using PITCHLOCK, could you just try
reverting the last line of your patch, the one that says

vmw_write(vmw_priv, SVGA_REG_BYTES_PER_LINE, info->fix.line_length);

That should hopefully fix the new bug and leave fbdev working as you
intended.

Thanks,
Thomas