Re: [PATCH v3] drm/i915: Honor SSC quirk table over the default, unless set by user

Michel Alexandre Salim
2011-11-10T09:46:58Z

On Wed, 2011-11-09 at 10:07 -0800, Keith Packard wrote:
> On Wed, 09 Nov 2011 17:30:29 +0100, Michel Alexandre Salim <salimma@fedoraproject.org> wrote:
> > Additional note: while I've not touched the line since it does not
> > affect me, it seems that i915_panel_use_ssc *cannot* be less than 0
> > since that variable is declared as unsigned.
>
> Oops. That's the bug here -- we're supposed to make it so that the
> command line can override the quirks, but there's no way to use a quirk
> given the mis-declared parameter.
Ah, now everything makes sense.
>
> This is untested...
>
Tested and it works fine:
- without extra parameter, the blacklist is used
- with i915.lvds_use_ssc=1, SSC use is enforced and the display turns
black on my unsupported hardware
- with i915.lvds_use_ssc=0, SSC is disabled

(ps the PGP/MIME signature made it hard to just extract the
git-formatted email; I ended up just editing the message by hand before
'git am')

> From e64ecadef40e3c2035cd4e9b967ffd83489bdea0 Mon Sep 17 00:00:00 2001
> From: Keith Packard <keithp@keithp.com>
> Date: Wed, 9 Nov 2011 09:57:50 -0800
> Subject: [PATCH] drm/i915: Module parameters using '-1' as default must be
> signed type
>
> Testing i915_panel_use_ssc for the default value was broken, so the
> driver would never autodetect the correct value.
>
> Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Michel Alexandre Salim <salimma@fedoraproject.org>
Tested-by: Michel Alexandre Salim <salimma@fedoraproject.org>

Should I send the patch that I applied with those added lines? Probably
not necessary.

Thanks,

--
Michel