[PATCH 4/4] ARM: PXA: PXAFB: don't disable controller on cpufreq transition if overlay is in use

Vasily Khoruzhick anarsoul at gmail.com
Fri Mar 11 04:20:50 EST 2011

It's not safe to disable controller if overlay(s) is enabled (results in
system hang). So we avoid to disable controller in this case. Userspace
should choose proper governor to avoid freq changing when overlay is in
use, otherwise LCD may blink.

Signed-off-by: Vasily Khoruzhick <anarsoul at gmail.com>
 drivers/video/pxafb.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/video/pxafb.c b/drivers/video/pxafb.c
index a3bdcc1..a2e5b51 100644
--- a/drivers/video/pxafb.c
+++ b/drivers/video/pxafb.c
@@ -1648,7 +1648,8 @@ pxafb_freq_transition(struct notifier_block *nb, unsigned long val, void *data)
 	switch (val) {
-		set_ctrlr_state(fbi, C_DISABLE_CLKCHANGE);
+		if (!fbi->overlay[0].usage && !fbi->overlay[1].usage)
+			set_ctrlr_state(fbi, C_DISABLE_CLKCHANGE);

More information about the linux-arm-kernel mailing list