linux-kernel - Re: [PATCH 1/1] drm/vmwgfx: correct fb_fix_screeninfo.line

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <53B16006.1080605@vmware.com>
Date:	Mon, 30 Jun 2014 15:03:02 +0200
From:	Thomas Hellstrom <thellstrom@...are.com>
To:	Christopher Friedt <chrisfriedt@...il.com>
CC:	dri-devel <dri-devel@...ts.freedesktop.org>,
	linux-kernel@...r.kernel.org, Dave Airlie <airlied@...il.com>,
	linux-graphics-maintainer@...are.com
Subject: Re: [PATCH 1/1] drm/vmwgfx: correct fb_fix_screeninfo.line_length

On 06/30/2014 02:49 PM, Christopher Friedt wrote:
> On Mon, Jun 30, 2014 at 8:39 AM, Thomas Hellstrom <thellstrom@...are.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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/