linux-kernel - [ 44/57] drm/i915: preserve pipe A quirk in i9xx_set

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: <20131003040639.607282223@linuxfoundation.org>
Date:	Wed,  2 Oct 2013 21:09:10 -0700
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org, Meelis Roos <mroos@...ee>,
	Chris Wilson <chris@...is-wilson.co.uk>,
	Ville Syrjälä 
	<ville.syrjala@...ux.intel.com>,
	Daniel Vetter <daniel.vetter@...ll.ch>
Subject: [ 44/57] drm/i915: preserve pipe A quirk in i9xx_set_pipeconf

3.11-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Daniel Vetter <daniel.vetter@...ll.ch>

commit 67c72a12254101d4e8d9b9f3a02646ba0be84a2d upstream.

This regression has been introduced in

commit 9f11a9e4e50006b615ba94722dfc33ced89664cf
Author: Daniel Vetter <daniel.vetter@...ll.ch>
Date:   Thu Jun 13 00:54:58 2013 +0200

    drm/i915: set up PIPECONF explicitly for i9xx/vlv platforms

Ville brough up the idea that this is just the pipe A quirk gone
wrong.

Note that after resume the bios might or might not have enabled pipe A
already.  We have a bit of magic to make sure that on resume we set up
a decent mode for pipe A, but I fear if I just smash pipe A to always
on we'd enable it in a bogus state and hang the hw. Hence the
readback.

v2: Clarify the logic a bit as suggested by Chris. Also amend the
commit message to clarify why we don't unconditionally enable the
pipe.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=66462
References: https://lkml.org/lkml/2013/8/26/238
Cc: Meelis Roos <mroos@...ee>
Cc: Chris Wilson <chris@...is-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@...ux.intel.com>
Reviewed-by: Chris Wilson <chris@...is-wilson.co.uk>
[danvet: Use |= instead of = as suggested by Chris.]
Signed-off-by: Daniel Vetter <daniel.vetter@...ll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/gpu/drm/i915/intel_display.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4735,6 +4735,10 @@ static void i9xx_set_pipeconf(struct int
 
 	pipeconf = 0;
 
+	if (dev_priv->quirks & QUIRK_PIPEA_FORCE &&
+	    I915_READ(PIPECONF(intel_crtc->pipe)) & PIPECONF_ENABLE)
+		pipeconf |= PIPECONF_ENABLE;
+
 	if (intel_crtc->pipe == 0 && INTEL_INFO(dev)->gen < 4) {
 		/* Enable pixel doubling when the dot clock is > 90% of the (display)
 		 * core speed.


--
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/