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* [PATCH] drm/i915: Avoid PPS HW/SW state mismatch due to rounding
@ 2017-11-29 17:51 Imre Deak
  2017-11-29 18:04 ` Ville Syrjälä
                   ` (4 more replies)
  0 siblings, 5 replies; 8+ messages in thread
From: Imre Deak @ 2017-11-29 17:51 UTC (permalink / raw)
  To: intel-gfx; +Cc: joks

We store a SW state of the t11_t12 timing in 100usec units but have to
program it in 100msec as required by HW. The rounding used during
programming means there will be a mismatch between the SW and HW states
of this value triggering a "PPS state mismatch" error. Avoid this by
storing the already rounded-up value in the SW state.

Note that we still calculate panel_power_cycle_delay with the finer
100usec granularity to avoid any needless waits using that version of
the delay.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103903
Cc: joks <joks@linux.pl>
Signed-off-by: Imre Deak <imre.deak@intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 957735c0b4c6..27d2529a3416 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -5355,6 +5355,12 @@ intel_dp_init_panel_power_sequencer(struct intel_dp *intel_dp)
 	 */
 	final->t8 = 1;
 	final->t9 = 1;
+
+	/*
+	 * HW has only a 100msec granularity for t11_t12 so round it up
+	 * accordingly.
+	 */
+	final->t11_t12 = roundup(final->t11_t12, 100 * 10);
 }
 
 static void
-- 
2.13.2

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^ permalink raw reply related	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2017-11-30 15:12 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-11-29 17:51 [PATCH] drm/i915: Avoid PPS HW/SW state mismatch due to rounding Imre Deak
2017-11-29 18:04 ` Ville Syrjälä
2017-11-29 18:17   ` Imre Deak
2017-11-30  9:09 ` ✗ Fi.CI.BAT: failure for " Patchwork
2017-11-30 10:45 ` ✓ Fi.CI.BAT: success " Patchwork
2017-11-30 12:24   ` Imre Deak
2017-11-30 13:31 ` ✓ Fi.CI.IGT: " Patchwork
2017-11-30 15:12 ` ✗ Fi.CI.BAT: failure " Patchwork

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