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author | Maarten Lankhorst <maarten.lankhorst@linux.intel.com> | 2016-01-06 12:54:43 (GMT) |
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committer | Maarten Lankhorst <maarten.lankhorst@linux.intel.com> | 2016-01-06 13:20:30 (GMT) |
commit | 31d10b5701964ed8806193807279ee7b4235e491 (patch) | |
tree | 4117a8fd653f9361896961854786666036a2aa69 /drivers/gpu | |
parent | d93c037246104e403436ffe339bcb832185d0627 (diff) | |
download | linux-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.c | 13 |
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 |