[PATCH 0/4] drm/i915: Avoid early timeout due to wait_for_atomic

Imre Deak
2016-06-28T10:37:36Z

If called from non-atomic context wait_for_atomic{,_us} can fail even
though the given condition becomes true before the timeout passes. I
noticed this via sporadic timeouts during PLL locking on BXT (fixed by
patch 1). The WARN in wait_for_atomic would be also triggered, alas I
didn't have extra debugging enabled.

host2guc_action() has the same issue. I left that as-is since it seems
to be on a critical path where the overhead of the jiffies based
wait_for can be considerable. Due to the relatively long 10ms timeout
there this doesn't lead to early timeouts in any case.

CC: Chris Wilson <chris@chris-wilson.co.uk>
CC: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

Imre Deak (4):
drm/i915/bxt: Avoid early timeout during PLL enable
drm/i915/lpt: Avoid early timeout during FDI PHY reset
drm/i915/hsw: Avoid early timeout during LCPLL disable/restore
drm/i915: Avoid early timeout during AUX transfers

drivers/gpu/drm/i915/intel_display.c | 16 ++++++++--------
drivers/gpu/drm/i915/intel_dp.c | 2 +-
drivers/gpu/drm/i915/intel_dpll_mgr.c | 4 ++--
3 files changed, 11 insertions(+), 11 deletions(-)

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2.5.0