Re: [PATCH 1/1] drm/vmwgfx: correct fb_fix_screeninfo.line_length

[Thomas Hellstrom <thellstrom@vmware.com>]

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