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drm/vc4: hdmi: Make sure the device is powered with CEC

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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: 15b4511a4a ("drm/vc4: add HDMI CEC support")
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20210819135931.895976-6-maxime@cerno.tech
This commit is contained in:
Maxime Ripard 2021-08-19 15:59:30 +02:00
parent 724fc856c0
commit 20b0dfa86b
No known key found for this signature in database
GPG key ID: E3EF0D6F671851C5
1 changed files with 9 additions and 1 deletions
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10
drivers/gpu/drm/vc4/vc4_hdmi.c
View file

@ -1741,8 +1741,14 @@ static int vc4_hdmi_cec_enable(struct cec_adapter *adap)
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);
@ -1785,6 +1791,8 @@ static int vc4_hdmi_cec_disable(struct cec_adapter *adap)
HDMI_WRITE(HDMI_CEC_CNTRL_5, HDMI_READ(HDMI_CEC_CNTRL_5) |
VC4_HDMI_CEC_TX_SW_RESET | VC4_HDMI_CEC_RX_SW_RESET);
pm_runtime_put(&vc4_hdmi->pdev->dev);
return 0;
}