Commit 84d84cb7 authored by Chris Wilson's avatar Chris Wilson

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: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170411112705.12656-1-chris@chris-wilson.co.ukReviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
parent 6976e74b
...@@ -1601,7 +1601,7 @@ static int gen6_reset_engines(struct drm_i915_private *dev_priv, ...@@ -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. * Otherwise, the wait will timeout after @slow_timeout_ms milliseconds.
* For atomic context @slow_timeout_ms must be zero and @fast_timeout_us * 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 * 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 * 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, ...@@ -1623,16 +1623,18 @@ int __intel_wait_for_register_fw(struct drm_i915_private *dev_priv,
int ret; int ret;
/* Catch any overuse of this function */ /* 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 = -ETIMEDOUT;
ret = _wait_for(done, fast_timeout_us, 10); if (fast_timeout_us && fast_timeout_us <= 20000)
else
ret = _wait_for_atomic(done, fast_timeout_us, 0); ret = _wait_for_atomic(done, fast_timeout_us, 0);
if (ret) if (ret)
ret = wait_for(done, slow_timeout_ms); ret = wait_for(done, slow_timeout_ms);
if (out_value) if (out_value)
*out_value = reg_value; *out_value = reg_value;
return ret; return ret;
#undef done #undef done
} }
......
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