Le mar. 16 mai 2023 à 14:31, Robin Murphy <robin.murphy@xxxxxxx> a écrit : > > On 2023-05-16 13:16, Nicolas Chauvet wrote: > > Le mar. 16 mai 2023 à 13:45, Robin Murphy <robin.murphy@xxxxxxx> a écrit : > >> > >> On 2023-05-16 10:53, Nicolas Chauvet wrote: > > ... > >>> For what it worth, I've tried to test this serie with "grate patches" > >>> (1) rebased on top on 6.4-rc2, that would make use of the tegra-gart. > >>> That was on PAZ00 (with only 512M of RAM and 96M CMA still allocated). > >>> Unfortunately, this lead to the following errors with display problems > >>> (no character displayed in lxt-terminal and etc) > >> > >> Thanks for testing - it's quite possible I've made a silly mistake > >> somewhere, but just to double-check, does the same happen with the > >> existing driver if you boot with "tegra-gart.gart_debug=1" (or at least > >> enable the parameter via sysfs before the DRM driver gets going)? > > > > Using echo 1 > /sys/module/tegra_gart/parameters/gart_debug shows the > > same messages and the same artefacts (missing refreshed window > > content). > > Using "echo 0 > /sys/module/tegra_gart/parameters/gart_debug" revert > > back to normal... > > OK, cool, so it looks like a pre-existing bug in the caller, but I guess > it does mean that unconditionally enabling the checks isn't ideal until > that can be sorted out. Seems like I had a non-default option with tegra-drm that was controlling the way tegra-gart is used: https://github.com/grate-driver/linux/blob/master/drivers/gpu/drm/grate/gart.c#L19-L29 With option 4, occurrences of failing allocation are experienced more often than the default 0 options when only "scattered BOs are mapped". Also with the default option, no noticeable failure is seen. Thanks.
