Hi Priit, On Wed, Jan 16, 2019 at 07:58:54AM +0000, Priit Laes wrote: > > On Mon, Jan 14, 2019 at 01:29:34PM +0000, Priit Laes wrote: > > > I have a somewhat curious case with one HDMI/DVI screen that fails > > > to initialize properly every 6-7 boots. The display itself is also > > > somewhat flawed (missing HPD pin and the VSYNC/HSYNC pulse width > > > is set to 0 in EDID), but I suspect there could be some issues > > > regarding timing in A20 HDMI driver in Linux. > > > > ... > > > It doesn't look related to the clock rate itself, since it doesn't > > change between the two cases. However, in one case the DDC clock is > > enabled and in the other it's disabled. > > > > Was it taken at the same time? Maybe you can try with that patch? > > http://code.bulix.org/z7jmkm-555344?raw > > Thanks, after doing ~50+ boots I haven't seen a single failure. > > Previously I had following failure cases which are now both fixed: > > a) Linux without u-boot HDMI, where one in every 6-7 boots failed. > b) u--boot with hdmi enabled switching to simplefb and then switching > to kms, where previously all boots ended up with garbled screen. So it's not really a fix, but it really looks like the clock is not enabled when it should. Can you describe your test scenario a bit more? What are you doing exactly, just booting? When do you start using the display? When did you capture the debugfs output that you pasted? Thanks! Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
