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| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2017-05-10 17:19:32 +0200 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2017-05-10 20:06:41 +0200 |
| commit | ff26ffa8ee267dcbd27a5d81cb21d1c41bfdb44a (patch) | |
| tree | 86a0b07e6268b8acf7a230c53a62828cb9c854fc /drivers/gpu | |
| parent | e11ffddba1f363f9713442500f779693b0d7cc19 (diff) | |
| download | lwn-ff26ffa8ee267dcbd27a5d81cb21d1c41bfdb44a.tar.gz lwn-ff26ffa8ee267dcbd27a5d81cb21d1c41bfdb44a.zip | |
drm/i915: Fix __intel_wait_for_register_fw to not sleep in atomic
The unconditionally fallback to the blocking wait_for resulted in
impressive fireworks at boot-up on my snb here. Make sure if we set
the slow timeout to 0 that we never ever sleep. The tail of the
callchain was
intel_wait_for_register
-> __intel_wait_for_register_fw
-> usleep_range
-> BOOM
It blew up in intel_crt_detect load detection code on the
ADPA_CRT_HOTPLUG_FORCE_TRIGGER in the ADPA register.
v2: Shut up gcc.
v3: Use uninitialized_var() (Chris).
Fixes: 0564654340e2 ("drm/i915: Acquire uncore.lock over intel_uncore_wait_for_register()")
Cc: Chris 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>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1494429572-15118-1-git-send-email-daniel.vetter@ffwll.ch
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_uncore.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c index 2c628df6d9d5..08d7d08438c0 100644 --- a/drivers/gpu/drm/i915/intel_uncore.c +++ b/drivers/gpu/drm/i915/intel_uncore.c @@ -1610,7 +1610,7 @@ int __intel_wait_for_register_fw(struct drm_i915_private *dev_priv, unsigned int slow_timeout_ms, u32 *out_value) { - u32 reg_value; + u32 uninitialized_var(reg_value); #define done (((reg_value = I915_READ_FW(reg)) & mask) == value) int ret; @@ -1621,7 +1621,7 @@ int __intel_wait_for_register_fw(struct drm_i915_private *dev_priv, ret = -ETIMEDOUT; if (fast_timeout_us && fast_timeout_us <= 20000) ret = _wait_for_atomic(done, fast_timeout_us, 0); - if (ret) + if (ret && slow_timeout_ms) ret = wait_for(done, slow_timeout_ms); if (out_value) |