Our usleep_range(min, max) implementation today is only taking account

of the min value to delay.  On the iMac11,2 this was too short, causing
a timeout in the DP AUX transaction retry loop, leaving the eDP dark
after the KMS initialization attempt.  Affected code line for reference:

sys/dev/pci/drm/drm_dp_helper.c:771, revision 1.11

Therefore we change the behavior of usleep_range(min, max) to delay
the average value of min and max instead, which finally fixes the KMS
initialization on the iMac11,2.

Help and ok jsg@

1 files changed, 1 insertions, 1 deletions

diff --git a/sys/dev/pci/drm/include/linux/delay.h b/sys/dev/pci/drm/include/linux/delay.h
index 19f0ef92204..b786cb8620a 100644
--- a/sys/dev/pci/drm/include/linux/delay.h
+++ b/sys/dev/pci/drm/include/linux/delay.h
@@ -20,7 +20,7 @@ ndelay(unsigned long nsecs)
 static inline void
 usleep_range(unsigned long min, unsigned long max)
 {
-	DELAY(min);
+	DELAY((min + max) / 2);
 }
 
 static inline void