From: Maxime Ripard maxime@cerno.tech
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@raspberrypi.com Signed-off-by: Maxime Ripard maxime@cerno.tech Link: https://patchwork.freedesktop.org/patch/msgid/20210819135931.895976-6-maxime... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 @@ -1735,8 +1735,14 @@ 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); @@ -1882,6 +1888,8 @@ static int vc4_hdmi_cec_init(struct vc4_ if (ret < 0) goto err_remove_handlers;
+ pm_runtime_put(&vc4_hdmi->pdev->dev); + return 0;
err_remove_handlers: