drm/i915/guc/slpc: Apply min softlimit correctly

[ Upstream commit 3e49de73fb ]

The scenario being fixed here is depicted in the following sequence-

modprobe i915
echo 1 > /sys/class/drm/card0/gt/gt0/slpc_ignore_eff_freq
echo 300 > /sys/class/drm/card0/gt_min_freq_mhz (RPn)
cat /sys/class/drm/card0/gt_cur_freq_mhz --> cur == RPn as expected
echo 1 > /sys/kernel/debug/dri/0/gt0/reset --> reset
cat /sys/class/drm/card0/gt_min_freq_mhz --> cached freq is RPn
cat /sys/class/drm/card0/gt_cur_freq_mhz --> it's not RPn, but RPe!!

When SLPC reinitializes, it sets SLPC min freq to efficient frequency.
Even if we disable efficient freq post that, we should restore the cached
min freq (via H2G) for it to take effect.

v2: Clarify commit message (Ashutosh)

Fixes: 95ccf312a1 ("drm/i915/guc/slpc: Allow SLPC to use efficient frequency")
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230621014257.1769564-1-vinay.belgaumkar@intel.com
(cherry picked from commit da86b2b13f)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Vinay Belgaumkar 2023-06-20 18:42:57 -07:00 committed by Greg Kroah-Hartman
parent 61070305d5
commit dcb526d768
1 changed files with 1 additions and 1 deletions

View File

@ -580,7 +580,7 @@ static int slpc_set_softlimits(struct intel_guc_slpc *slpc)
if (unlikely(ret))
return ret;
slpc_to_gt(slpc)->defaults.min_freq = slpc->min_freq_softlimit;
} else if (slpc->min_freq_softlimit != slpc->min_freq) {
} else {
return intel_guc_slpc_set_min_freq(slpc,
slpc->min_freq_softlimit);
}