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

From: [email-masked] (Tony Lindgren)
Date: Fri, 9 May 2014 07:37:49 -0700

* Tomi Valkeinen <[email-masked]> [140509 01:02]:
> 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?

OK pasted to the other email in this thread.

Tony