Hi Maxime, Am 06.07.21 um 15:21 schrieb Maxime Ripard: > Hi Stefan, > > On Tue, Jul 06, 2021 at 12:48:05PM +0200, Stefan Wahren wrote: >> Am 06.07.21 um 11:58 schrieb Maxime Ripard: >>> Hi, >>> >>> On Mon, Jul 05, 2021 at 11:36:34PM +0200, Stefan Wahren wrote: >>>> Commit "drm/vc4: hdmi: Convert to gpiod" changes the behavior of >>>> vc4_hdmi_connector_detect() which results into CPU hangs in case there >>>> is no HDMI connected. Let's restore the old behavior. >>>> >>>> Reported-by: Nathan Chancellor <nathan@xxxxxxxxxx> >>>> Reported-by: Ojaswin Mujoo <ojaswin98@xxxxxxxxx> >>>> Fixes: 6800234ceee0 ("drm/vc4: hdmi: Convert to gpiod") >>>> Signed-off-by: Stefan Wahren <stefan.wahren@xxxxxxxx> >>> I already sent this patch last week: >>> >>> https://lore.kernel.org/dri-devel/20210628124257.140453-3-maxime@xxxxxxxxxx/ >> oops, i only looked in the July archive. >> >>> I'm not entirely sure how this could create a CPU hang though. Withouth >>> this patch, if the HPD GPIO is low, we would first try to retrieve the >>> EDID, and then if it doesn't we would read the hotplug register. >> Yes, the real issue has been revealed by the original change and this >> patch only "hides" it again. >>> The first is using a separate i2c controller (and even if it was in the >>> same power domain, we have the pm_runtime_resume call), and the register >>> read should be fine too? >> Sorry, i don't have a clue and time for further investigations. >> >> Does it mean, you are not able to reproduce this issue? > On next-20210706 at least it works fine for me without an HDMI monitor > connected, yes: which configuration do you use? Did you tried arm/multi_v7_defconfig? I tried yesterday mainline ("a180bd1d7e16173d965b263c5a536aa40afa2a2a") with multi_v7_defconfig and the issue was there.