summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--drivers/gpu/drm/i915/intel_drv.h13
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 8720a67395f8..18bba6e25e1e 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -33,12 +33,21 @@
#include <drm/drm_fb_helper.h>
#include <drm/drm_dp_helper.h>
+/**
+ * _wait_for - magic (register) wait macro
+ *
+ * Does the right thing for modeset paths when run under kdgb or similar atomic
+ * contexts. Note that it's important that we check the condition again after
+ * having timed out, since the timeout could be due to preemption or similar and
+ * we've never had a chance to check the condition before the timeout.
+ */
#define _wait_for(COND, MS, W) ({ \
- unsigned long timeout__ = jiffies + msecs_to_jiffies(MS); \
+ unsigned long timeout__ = jiffies + msecs_to_jiffies(MS) + 1; \
int ret__ = 0; \
while (!(COND)) { \
if (time_after(jiffies, timeout__)) { \
- ret__ = -ETIMEDOUT; \
+ if (!(COND)) \
+ ret__ = -ETIMEDOUT; \
break; \
} \
if (W && drm_can_sleep()) { \