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

Tony Lindgren
2014-05-09T14:37:49Z

* Tomi Valkeinen <tomi.valkeinen@ti.com> [140509 01:02]:
> On 09/05/14 02:20, Tony Lindgren wrote:
> > * Tony Lindgren <tony@atomide.com> [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