On 2015-11-25 18:22, Philipp Zabel wrote: > Am Mittwoch, den 15.07.2015, 17:50 +0200 schrieb Manfred Schlaegl: >> To get full support for parallel and LVDS displays with drm: >> Add representation for clock and data enable polarity in drm_display_mode >> flags (similar to HSYNC/VSYNC polarity) and update conversion functions >> from/to videomode accordingly. >> >> This is especially important for embedded devices where parallel(RGB) and >> LVDS displays are still widely used and drm already plays an important >> role. >> >> Tested on Freescale i.MX53(parallel) and i.MX6(LVDS). >> >> Background: >> There was the ability to set polarity of clock and data enable signals >> in devicetree(display-timing), struct display_timing and struct videomode, >> but there was no representation for this in struct drm_display_mode. >> Example on Freescale i.MX53/i.MX6 SoC's: >> * A parallel display using different clock polarity is set up using >> display-timing in devicetree >> * ipuv3 parallel outputs clock with wrong polarity >> >> Signed-off-by: Manfred Schlaegl <manfred.schlaegl@xxxxxx> > > Any comments on whether data enable and pixel clock polarity flags can > be added to the visible DRM_MODE_FLAGs, and if not, where else this > information should be kept? struct drm_display_info? > > This patch and the following IPUv3 patch are useful and necessary for > quite some panels connected to i.MX SoCs, but adding DRM_MODE_FLAGs is > somewhat out of my jurisdiction. > > best regards > Philipp > Good to see that this discussion is triggered. State of the sent patches respective to git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git (78c4a49) * [RFC PATCH 1/2] drm: add support for for clk and de polarity * applies unmodified * [RFC PATCH 2/2] gpu: ipu-v3: use clock and de polarity from videomode * does not apply -> but this can be fixed with corrections of line offsets (using patch) >From a code review I think the modifications must work, but I did no testing on kernel versions newer than 4.1.13. On demand, I can redo tests on some of our i.MX53 (parallel) and i.MX6 (lvds) boards and send actual patches. best regards, Manfred _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
