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Trying to set IPU parent clock to TVE in 3.14 kernel with device tree

Question asked by belgianwaffle on Oct 9, 2015
Latest reply on Oct 27, 2015 by alejandrolozano

Hi,

We recently ported our custom imx51 board from Linux 2.6 to Linux 3.14.

Our display was rock solid with 2.6 no matter the length of the cable. Well with 3.14 we're having problems with the longer cable. The pixel clk is attenuated and has hiccups every n clock cycles depending on the frequency.

Upon further inspection of the IPU driver, the IPU parent is the ipu_gate clock.

In the older kernel we were using TVE (not external) as the parent clock to the IPU, but in the new kernel I'm having trouble figuring out where to set the IPU parent to TVE.

I tried to set the IPU parent in the imx51.dtsi file to TVE, but the choices are TVE gated or pre-divider so it doesn't work.

I tried reading through ipu-di.c and ipu-common.c

I tried different clock parent setups in clk-imx51-imx53.c, but no cigar.

Any help would be appreciated.

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