Hi All, I am working on a platform based on the Renesas RZ/G2 SoC family.
This chip uses the rcar-du driver for the display. I would like to submit a
patch to address the fact that the driver does not check/honor the flag
DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE. My issue is that I would like to make as
small a change to the driver as possible, but the panel bus_flags don't seem to
even make it to the crtc driver. The crtc driver seems to use adjusted_mode to
set the HSYNC and VSYNC polarity and as I said ignores the pixel clock polarity
leaving it at the default of driving on the falling edge. In my investigations
so far I have not figured out how to chase the pointers from the CRTC to the
bridge to the panel in order to be able to look at bus_flags. My current
approach also modifies the encoder initialization to cache the needed panel and
then find the attached encoder during CRTC initialization to find the bus
flags. This seems like a lot of work and not something that would be accepted
as a patch. The OMAP DSS seems to have problems accessing this flag as well.
The TI driver goes so far as to document the current approach as a HACK and
suggest a fairly large change to the driver to address the problem. Am I
missing something? Is there an easy way to get from a drm_crtc to a drm_panel
that is in the same pipeline?
Any pointers would be greatly appreciated!
Thanks!
-charles
