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authorMaarten Lankhorst <maarten.lankhorst@linux.intel.com>2016-01-06 12:54:43 (GMT)
committerMaarten Lankhorst <maarten.lankhorst@linux.intel.com>2016-01-06 13:20:30 (GMT)
commit31d10b5701964ed8806193807279ee7b4235e491 (patch)
tree4117a8fd653f9361896961854786666036a2aa69 /drivers/gpu
parentd93c037246104e403436ffe339bcb832185d0627 (diff)
downloadlinux-31d10b5701964ed8806193807279ee7b4235e491.tar.xz
drm/i915: Allow fuzzy matching in intel_compare_link_m_n
This prevents a unnecessary modeset on a dell XPS 13 (2016). N is always a power of 2, which means that for fuzzy matching we should compare for inequality on the n values, then do fuzzy matching on the m values. Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Tested-by: Kenneth Graunke <kenneth@whitecape.org> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/568D0E93.304@linux.intel.com
Diffstat (limited to 'drivers/gpu')
-rw-r--r--drivers/gpu/drm/i915/intel_display.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 043adfa..ab0b406 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12577,19 +12577,22 @@ intel_compare_m_n(unsigned int m, unsigned int n,
BUILD_BUG_ON(DATA_LINK_M_N_MASK > INT_MAX);
- if (m > m2) {
- while (m > m2) {
+ if (n > n2) {
+ while (n > n2) {
m2 <<= 1;
n2 <<= 1;
}
- } else if (m < m2) {
- while (m < m2) {
+ } else if (n < n2) {
+ while (n < n2) {
m <<= 1;
n <<= 1;
}
}
- return m == m2 && n == n2;
+ if (n != n2)
+ return false;
+
+ return intel_fuzzy_clock_check(m, m2);
}
static bool