From 0ba6ff7f5632f01143911e307be538ecc62e5094 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Thu, 19 Aug 2021 15:59:30 +0200 Subject: [PATCH] drm/vc4: hdmi: Make sure the device is powered with CEC 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 Signed-off-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20210819135931.895976-6-maxime@cerno.tech --- 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 @@ -1753,8 +1753,14 @@ static int vc4_hdmi_cec_enable(struct ce 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); @@ -1797,6 +1803,8 @@ static int vc4_hdmi_cec_disable(struct c 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; }