[PATCH 0/2] drm/tilcdc drm/i2c/tda998x workaround for sync issues on TI SoC

Darren Etheridge detheridge at ti.com
Thu Aug 1 07:29:00 PDT 2013


Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com> wrote on Wed [2013-Jul-31 22:21:20 +0200]:
> Darren,
> 
> I now fully understand the issues of AM335x's LCD controller and your
> fix for it. I suggest to clarify the comments you added to tilcdc to
> allow others to understand it more quickly.
> 
Sebastian,
Thanks for looking at my proposed changes, you understand this sync
stuff very well so I appreciate your input that this is actually an
acceptable workaround.

> Actually, the LCD controller always aligns vsync to the second edge
> of hsync, which will never give VESA-compliant sync. The (elegant)
> workaround you are proposing is to align both rising edges, so at
> least TDA998x can sync on those with some hskew added. Lucky you that
> it ignores hsync length but only looks for rising HS/VS edges ;)
Yes we definitely got lucky with this one, good thing the NXP
supported that reference pixel position, as I was out of options from
the lcd controller side of things to adjust the horizontal position. 

> 
> Should we prepare a new patch set comprising the following patches?
> 
> Russell King:
> drm/i2c: nxp-tda998x: fix EDID reading on TDA19988 devices
> drm/i2c: nxp-tda998x: ensure VIP output mux is properly set
> drm/i2c: nxp-tda998x: fix npix/nline programming
> drm/i2c: nxp-tda998x: prepare for video input configuration
> drm/i2c: nxp-tda998x: add video and audio input configuration
> 
> Sebastian Hesselbarth:
> drm/i2c: tda998x: fix sync generation and calculation
> 
> Darren Etheridge:
> drm/i2c/tda998x prepare for tilcdc sync workaround
> drm/tilcdc fixup mode to workaound sync for tda998x
> 
> Or do we keep them separated and possibly resend them if David cannot
> find them anymore?
I vote we submit a complete series that we can all test, there were quite
a lot of versions of things in flight at the same time so I am sure
David would appreciate a consolidated version.  
The only thing I have not tested is audio support, but as the original 
driver did not have that anyway I don't consider it blocking if it is 
working for CuBox.

Darren


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