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

[Rob Clark]

On Thu, Jul 25, 2013 at 2:32 PM, Darren Etheridge <detheridge at ti.com> wrote:
> Russell King and Sebastian Hasselbarth had proposed some very good changes
> for the tda998x HDMI encoder driver.  But when those changes were tested
> on BeagleBone Black against the tilcdc driver many modes would no longer
> display correctly.  After analyzing the sync signals from the TI lcd contoller
> to the nxp it is apparent that the hsync/vsync's are not rising at the same
> time as per the VESA spec and this is causing the HDMI encoder to get
> messed up and failing to lock correctly.
>
> This series of patches should be applied on top of:
>
> Russell King's
> rmk's Dove DRM/TDA19988 Cubox driver series
>
> Sebastian Hasselbarth's
> drm/i2c: tda998x: fix sync generation and calculation
>
> I have done as much of the change as I can in the tilcdc driver but there
> is a small unavoidable change in the tda998x driver.  However I have been
> careful not to break anything from the Dove drivers perspective. It
> would be great if somebody can test on Cubox and confirm that.
>
> This patch set inverts the hsync signal coming from the tilcdc so the NXP
> is kept happy and then shifts the output to the right to compensate for the
> sync timing issues.  Display modes from the NXP have been verified using a
> HDMI analyzer and are reporting correct timings at the output stage.
>
> Hopefully this will allow the dove/tda driver changes to progress now that
> were blocked as per this discussion:
> http://lists.freedesktop.org/archives/dri-devel/2013-July/040900.html
>

Good find Darren!  The patches look good to me from a quick review.
It would be good to get a tested-by from someone on cubox, but it is
good that we finally found the issue so that we can unblock further
tda998x development.

For the series:

Reviewed-by: Rob Clark <robdclark at gmail.com>


> Darren Etheridge (2):
>   drm/i2c/tda998x prepare for tilcdc sync workaround
>   drm/tilcdc fixup mode to workaound sync for tda998x
>
>  drivers/gpu/drm/i2c/tda998x_drv.c     |   10 ++++++++++
>  drivers/gpu/drm/tilcdc/tilcdc_crtc.c  |    7 ++++++-
>  drivers/gpu/drm/tilcdc/tilcdc_slave.c |   21 ++++++++++++++++++++-
>  3 files changed, 36 insertions(+), 2 deletions(-)
>