This is a note to let you know that I've just added the patch titled
drm/radeon/ci: disable mclk switching for high refresh rates (v2)
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-radeon-ci-disable-mclk-switching-for-high-refresh-rates-v2.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 58d7e3e427db1bd68f33025519a9468140280a75 Mon Sep 17 00:00:00 2001
From: Alex Deucher <alexander.deucher@xxxxxxx>
Date: Thu, 11 May 2017 13:14:14 -0400
Subject: drm/radeon/ci: disable mclk switching for high refresh rates (v2)
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From: Alex Deucher <alexander.deucher@xxxxxxx>
commit 58d7e3e427db1bd68f33025519a9468140280a75 upstream.
Even if the vblank period would allow it, it still seems to
be problematic on some cards.
v2: fix logic inversion (Nils)
bug: https://bugs.freedesktop.org/show_bug.cgi?id=96868
Acked-by: Christian König <christian.koenig@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/radeon/ci_dpm.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/drivers/gpu/drm/radeon/ci_dpm.c
+++ b/drivers/gpu/drm/radeon/ci_dpm.c
@@ -776,6 +776,12 @@ bool ci_dpm_vblank_too_short(struct rade
u32 vblank_time = r600_dpm_get_vblank_time(rdev);
u32 switch_limit = pi->mem_gddr5 ? 450 : 300;
+ /* disable mclk switching if the refresh is >120Hz, even if the
+ * blanking period would allow it
+ */
+ if (r600_dpm_get_vrefresh(rdev) > 120)
+ return true;
+
if (vblank_time < switch_limit)
return true;
else
Patches currently in stable-queue which might be from alexander.deucher@xxxxxxx are
queue-4.4/drm-radeon-ci-disable-mclk-switching-for-high-refresh-rates-v2.patch
queue-4.4/drm-radeon-unbreak-hpd-handling-for-r600.patch