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@raspberrypi.com Signed-off-by: Maxime Ripard maxime@cerno.tech --- drivers/gpu/drm/vc4/vc4_hdmi.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index bfa35e32052f..53647ce902ae 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -1745,8 +1745,14 @@ 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); @@ -1789,6 +1795,8 @@ 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; }