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

stable inclusion
from stable-v5.10.97
commit ac4ba79bb02881ed714adaa89faee601a18bff6d
bugzilla: https://gitee.com/openeuler/kernel/issues/I55O0O

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ac4ba79bb02881ed714adaa89faee601a18bff6d

--------------------------------

Commit 20b0dfa8 upstream.

The original commit depended on a rework commit (724fc856 ("drm/vc4:
hdmi: Split the CEC disable / enable functions in two")) that
(rightfully) didn't reach stable.

However, probably because the context changed, when the patch was
applied to stable the pm_runtime_put called got moved to the end of the
vc4_hdmi_cec_adap_enable function (that would have become
vc4_hdmi_cec_disable with the rework) to vc4_hdmi_cec_init.

This means that at probe time, we now drop our reference to the clocks
and power domains and thus end up with a CPU hang when the CPU tries to
access registers.

The call to pm_runtime_resume_and_get() is also problematic since the
.adap_enable CEC hook is called both to enable and to disable the
controller. That means that we'll now call pm_runtime_resume_and_get()
at disable time as well, messing with the reference counting.

The behaviour we should have though would be to have
pm_runtime_resume_and_get() called when the CEC controller is enabled,
and pm_runtime_put when it's disabled.

We need to move things around a bit to behave that way, but it aligns
stable with upstream.

Cc: <stable@vger.kernel.org> # 5.10.x
Cc: <stable@vger.kernel.org> # 5.15.x
Cc: <stable@vger.kernel.org> # 5.16.x
Reported-by: NMichael Stapelberg <michael+drm@stapelberg.ch>
Signed-off-by: NMaxime Ripard <maxime@cerno.tech>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYu Liao <liaoyu15@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/gpu/drm/vc4/vc4_hdmi.c

@@ -1402,6 +1402,7 @@ static int vc4_hdmi_cec_adap_enable(struct cec_adapter *adap, bool enable)
 	u32 val;
 	int ret;
 
+	if (enable) {
 		ret = pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev);
 		if (ret)
 			return ret;
@@ -1413,7 +1414,6 @@ static int vc4_hdmi_cec_adap_enable(struct cec_adapter *adap, bool enable)
 		val |= ((4700 / usecs) << VC4_HDMI_CEC_CNT_TO_4700_US_SHIFT) |
 			((4500 / usecs) << VC4_HDMI_CEC_CNT_TO_4500_US_SHIFT);
 
-	if (enable) {
 		HDMI_WRITE(HDMI_CEC_CNTRL_5, val |
 			   VC4_HDMI_CEC_TX_SW_RESET | VC4_HDMI_CEC_RX_SW_RESET);
 		HDMI_WRITE(HDMI_CEC_CNTRL_5, val);
@@ -1439,7 +1439,10 @@ static int vc4_hdmi_cec_adap_enable(struct cec_adapter *adap, bool enable)
 		HDMI_WRITE(HDMI_CEC_CPU_MASK_SET, VC4_HDMI_CPU_CEC);
 		HDMI_WRITE(HDMI_CEC_CNTRL_5, val |
 			   VC4_HDMI_CEC_TX_SW_RESET | VC4_HDMI_CEC_RX_SW_RESET);
+
+		pm_runtime_put(&vc4_hdmi->pdev->dev);
 	}
+
 	return 0;
 }
 
@@ -1531,8 +1534,6 @@ static int vc4_hdmi_cec_init(struct vc4_hdmi *vc4_hdmi)
 	if (ret < 0)
 		goto err_delete_cec_adap;
 
-	pm_runtime_put(&vc4_hdmi->pdev->dev);
-
 	return 0;
 
 err_delete_cec_adap: