Subject: [PATCH 1/4] OMAPDSS: Fix DSS clock multiplier issue on 3703 and probably 3630

From: [email-masked] (Tomi Valkeinen)
Date: Fri, 9 May 2014 11:01:52 +0300

On 09/05/14 02:20, Tony Lindgren wrote:
> * Tony Lindgren <[email-masked]> [140429 16:53]:
>> Otherwise we can get often errors like the following and the
>> display won't come on:
>>
>> omapdss APPLY error: FIFO UNDERFLOW on gfx, disabling the overlay
>> omapdss APPLY error: SYNC_LOST on channel lcd, restarting
>> the output with video overlays disabled
>>
>> There are some earlier references to this issue:
>>
>> http://www.spinics.net/lists/linux-omap/msg59511.html
>> http://www.spinics.net/lists/linux-omap/msg59724.html
>>
>> It seems that it's safe to set the lower values even for 3630.
>> If we can confirm that 3630 works with the higher values
>> reliably we can add further detection.
> 
> BTW, I'm also seeing this warning on 3730-evm it may be related:
> 
> [    3.523101] ------------[ cut here ]------------
> [    3.528015] WARNING: CPU: 0 PID: 6 at drivers/video/fbdev/omap2/dss/dss.c:483 dss_set_fck_rate+0x6c/0x8c()
> [    3.538360] clk rate mismatch: 108000000 != 115200000
> [    3.543518] Modules linked in:

Hmm... Can you paste the clk_summary from debugfs? Somehow the clock
framework calculates the clock rate differently than the dss. Or do we
have different clock.dts files used for 3730 and 3630?

 Tomi

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: OpenPGP digital signature
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20140509/b346dde8/attachment.sig>