[alsa-devel] [PATCH 00/13] Remove mach-kirkwood and mach-dove

[Jean-Francois Moine]

On Mon, 30 Jun 2014 09:49:18 +0100
Russell King - ARM Linux <linux at arm.linux.org.uk> wrote:

> The problem is that the picture appears for about a second, then goes black
> for maybe a couple of seconds, then reappears for about a second and this
> cycle repeats.  Rebooting into the DT kernel doesn't fix it.  Rebooting
> back into the non-DT kernel does fix it.  Then if you boot back into the DT
> kernel it's back again.  Boot back into the non-DT kernel and it's again
> fixed.
> 
> I have compared register settings for the Si5351, LCD controllers and the
> TDA998x between the non-DT and DT versions, and can find no differences
> there.  Yet, DT kernels are the only kernels which exhibit this behaviour.
> Non-DT kernels (which I've run continuously including many reboots) for
> the last two years have *never* shown this problem.
> 
> I have also verified that the HDMI clock is correct.  The problem occurs
> at both 1080p and 720p resolutions (which are the two that are used during
> boot - I have the kernel using 720p, and Xorg uses 1080p.)
> 
> I should also point out that in both cases, it is the _same_ kernel binary
> (3.15) that I'm running - the DT test case just has the DT blob attached
> whereas the non-DT case boots without (and therefore falls back to the
> old platform stuff.)

Have you declared the LCD clock in dove.dtsi?

 	lcdclk: fixed-clock {
		compatible = "fixed-clock";
 		#clock-cells = <0>;
 		clock-frequency = <400000000>;
 	};

-- 
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