[PATCH 0/2] drm/vc4: hdmi: Fixes for the RaspberryPi 0-3 stalls

From: Maxime Ripard
Date: Thu Sep 29 2022 - 05:33:18 EST


Hi,

Here's a series addressing the current bug that has been reported for the
RaspberryPi3, where booting without an HDMI monitor attached and with vc4
compiled as a module will lead to a stuck system when the module is loaded.

This is due to the HSM clock not being initialized by anyone, and thus not
being functional once we start accessing the HDMI registers.

The first patch will fix this, and the second will make sure we avoid that
situation entirely in the future. This has been tested with 5.19.12. Earlier
versions might need a backport of 88110a9f6209 ("clk: bcm2835: fix
bcm2835_clock_choose_div").

Let me know what you think,
Maxime

To: Daniel Vetter <daniel@xxxxxxxx>
To: David Airlie <airlied@xxxxxxxx>
To: Emma Anholt <emma@xxxxxxxxxx>
To: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
To: Maxime Ripard <mripard@xxxxxxxxxx>
To: Thomas Zimmermann <tzimmermann@xxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Cc: Stefan Wahren <stefan.wahren@xxxxxxxx>
Link: https://lore.kernel.org/dri-devel/20220922145448.w3xfywkn5ecak2et@xxxxxxxxxxxxxx/
Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>

---
Maxime Ripard (2):
drm/vc4: hdmi: Enforce the minimum rate at runtime_resume
drm/vc4: hdmi: Check the HSM rate at runtime_resume

drivers/gpu/drm/vc4/vc4_hdmi.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)
---
base-commit: 58df6af8cea3c5377c0220d9fb47cbf85a216f54
change-id: 20220929-rpi-pi3-unplugged-fixes-5d61ea2cc383

Best regards,
--
Maxime Ripard <maxime@xxxxxxxxxx>