From 84d84cb7e20d3d2c6413c5f75634e88eb68a3f97 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 11 Apr 2017 12:27:05 +0100 Subject: [PATCH] drm/i915: Stop second guessing the caller for intel_uncore_wait_for_register() Allow the caller to use the fast_timeout_us to specify how long to wait within the atomic section, rather than transparently switching to a sleeping loop for larger values. This is required as some callsites may need a long wait and are in an atomic section. v2: Reinforce kerneldoc fast_timeout_us limit with a GEM_BUG_ON Signed-off-by: Chris Wilson Cc: Michal Wajdeczko Cc: Joonas Lahtinen Cc: Tvrtko Ursulin Link: http://patchwork.freedesktop.org/patch/msgid/20170411112705.12656-1-chris@chris-wilson.co.uk Reviewed-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/intel_uncore.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c index eb38392a2435..dded42db880b 100644 --- a/drivers/gpu/drm/i915/intel_uncore.c +++ b/drivers/gpu/drm/i915/intel_uncore.c @@ -1601,7 +1601,7 @@ static int gen6_reset_engines(struct drm_i915_private *dev_priv, * * Otherwise, the wait will timeout after @slow_timeout_ms milliseconds. * For atomic context @slow_timeout_ms must be zero and @fast_timeout_us - * must be not larger than 10 microseconds. + * must be not larger than 20,0000 microseconds. * * Note that this routine assumes the caller holds forcewake asserted, it is * not suitable for very long waits. See intel_wait_for_register() if you @@ -1623,16 +1623,18 @@ int __intel_wait_for_register_fw(struct drm_i915_private *dev_priv, int ret; /* Catch any overuse of this function */ - might_sleep_if(fast_timeout_us > 10 || slow_timeout_ms); + might_sleep_if(slow_timeout_ms); + GEM_BUG_ON(fast_timeout_us > 20000); - if (fast_timeout_us > 10) - ret = _wait_for(done, fast_timeout_us, 10); - else + ret = -ETIMEDOUT; + if (fast_timeout_us && fast_timeout_us <= 20000) ret = _wait_for_atomic(done, fast_timeout_us, 0); if (ret) ret = wait_for(done, slow_timeout_ms); + if (out_value) *out_value = reg_value; + return ret; #undef done }