imx: ipu: fix occasional hang following disabling of channel

It has been observed that some IMX6SDL SoC will hang appx 0.1% of boots between disabling the ipu channel and disabling DMA preceeding an OS boot unless an extra delay is added here.

The specific cause is still under investigation.

Signed-off-by Tim Harvey <[email protected]>

---
 drivers/video/ipu_common.c | 1 +
 1 file changed, 1 insertion(+)

drivers/video/ipu_common.c +1 -0

index 5873531..3c1bbbb 100644
@@ -1109,6 +1109,7 @@ int32_t ipu_disable_channel(ipu_channel_t channel)
 	if ((channel == MEM_BG_SYNC) || (channel == MEM_FG_SYNC) ||
 	    (channel == MEM_DC_SYNC)) {
 		ipu_dp_dc_disable(channel, 0);
+		mdelay(50);
 	}
 
 	/* Disable DMA channel(s) */

Signature · 1 line

1.9.1

Hi Tim,

Does your code base contain this patch[1]?
It probably addressed the same issue you meet.

[1] http://lists.denx.de/pipermail/u-boot/2014-February/174533.html

Regards,
Liu Ying