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>
This commit is contained in:
Imre Deak 2013-05-21 20:03:17 +03:00 committed by Daniel Vetter
parent e3de42b684
commit df97729f1b

View File

@ -1943,4 +1943,19 @@ static inline void __user *to_user_ptr(u64 address)
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