drm/i915: add msecs_to_jiffies_timeout to guarantee minimum duration
We need this to avoid premature timeouts whenever scheduling a timeout
based on the current jiffies value. For an explanation see [1].
The following patches will take the helper into use.
Once the more generic solution proposed in the thread at [1] is accepted
this patch can be reverted while keeping the follow-up patches.
[1] http://marc.info/?l=linux-kernel&m=136854294730957&w=2
Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index d5dcf7f..b9d00dc 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1943,4 +1943,19 @@
return (void __user *)(uintptr_t)address;
}
+static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m)
+{
+ unsigned long j = msecs_to_jiffies(m);
+
+ return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
+}
+
+static inline unsigned long
+timespec_to_jiffies_timeout(const struct timespec *value)
+{
+ unsigned long j = timespec_to_jiffies(value);
+
+ return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
+}
+
#endif