From 20b0dfa86bef0e80b41b0e5ac38b92f23b6f27f9 Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime@cerno.tech>
Date: Thu, 19 Aug 2021 15:59:30 +0200
Subject: [PATCH] drm/vc4: hdmi: Make sure the device is powered with CEC
Git-commit: 20b0dfa86bef0e80b41b0e5ac38b92f23b6f27f9
Patch-mainline: v5.17-rc1
References: git-fixes
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@cerno.tech
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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 1f13e0f00089..8cc84395f4cb 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -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;
}
--
2.31.1