drm/radeon/kms: use udelay for short delays

For usec delays use udelay instead of scheduling, this should
allow reclocking to happen faster. This also was the cause
of reported 33s delays at bootup on certain systems.

fixes: freedesktop.org bug 25506

Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/radeon/atom.c b/drivers/gpu/drm/radeon/atom.c
index 2a3df5599ab48b0056fc2a4ad4b2d37bac29b4a1..7f152f66f196394dc7ee1318e64d651d216dfe19 100644 (file)
--- a/drivers/gpu/drm/radeon/atom.c
+++ b/drivers/gpu/drm/radeon/atom.c
@@ -643,7 +643,7 @@ static void atom_op_delay(atom_exec_context *ctx, int *ptr, int arg)
        uint8_t count = U8((*ptr)++);
        SDEBUG("   count: %d\n", count);
        if (arg == ATOM_UNIT_MICROSEC)
-               schedule_timeout_uninterruptible(usecs_to_jiffies(count));
+               udelay(count);
        else
                schedule_timeout_uninterruptible(msecs_to_jiffies(count));
 }