This is a note to let you know that I've just added the patch titled
drm/vc4: hdmi: Make sure the device is powered with CEC
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-vc4-hdmi-make-sure-the-device-is-powered-with-cec.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 20b0dfa86bef0e80b41b0e5ac38b92f23b6f27f9 Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime@xxxxxxxxxx>
Date: Thu, 19 Aug 2021 15:59:30 +0200
Subject: drm/vc4: hdmi: Make sure the device is powered with CEC
From: Maxime Ripard <maxime@xxxxxxxxxx>
commit 20b0dfa86bef0e80b41b0e5ac38b92f23b6f27f9 upstream.
Similarly to what we encountered with the detect hook with DRM, nothing
actually prevents any of the CEC callback from being run while the HDMI
output is disabled.
However, this is an issue since any register access to the controller
when it's powered down will result in a silent hang.
Let's make sure we run the runtime_pm hooks when the CEC adapter is
opened and closed by the userspace to avoid that issue.
Fixes: 15b4511a4af6 ("drm/vc4: add HDMI CEC support")
Reviewed-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20210819135931.895976-6-maxime@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/vc4/vc4_hdmi.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -1399,8 +1399,14 @@ static int vc4_hdmi_cec_adap_enable(stru
struct vc4_hdmi *vc4_hdmi = cec_get_drvdata(adap);
/* clock period in microseconds */
const u32 usecs = 1000000 / CEC_CLOCK_FREQ;
- u32 val = HDMI_READ(HDMI_CEC_CNTRL_5);
+ u32 val;
+ int ret;
+
+ ret = pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev);
+ if (ret)
+ return ret;
+ val = HDMI_READ(HDMI_CEC_CNTRL_5);
val &= ~(VC4_HDMI_CEC_TX_SW_RESET | VC4_HDMI_CEC_RX_SW_RESET |
VC4_HDMI_CEC_CNT_TO_4700_US_MASK |
VC4_HDMI_CEC_CNT_TO_4500_US_MASK);
@@ -1525,6 +1531,8 @@ static int vc4_hdmi_cec_init(struct vc4_
if (ret < 0)
goto err_delete_cec_adap;
+ pm_runtime_put(&vc4_hdmi->pdev->dev);
+
return 0;
err_delete_cec_adap:
Patches currently in stable-queue which might be from maxime@xxxxxxxxxx are
queue-5.10/clk-bcm-2835-pick-the-closest-clock-rate.patch
queue-5.10/drm-vc4-hdmi-set-a-default-hsm-rate.patch
queue-5.10/clk-bcm-2835-remove-rounding-up-the-dividers.patch
queue-5.10/drm-vc4-hdmi-make-sure-the-device-is-powered-with-cec.patch
