@@ -1739,18 +1739,18 @@ static int vc4_hdmi_cec_adap_enable(struct cec_adapter *adap, bool enable)
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);
- val |= ((4700 / usecs) << VC4_HDMI_CEC_CNT_TO_4700_US_SHIFT) |
- ((4500 / usecs) << VC4_HDMI_CEC_CNT_TO_4500_US_SHIFT);
-
if (enable) {
+ 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);
+ val |= ((4700 / usecs) << VC4_HDMI_CEC_CNT_TO_4700_US_SHIFT) |
+ ((4500 / usecs) << VC4_HDMI_CEC_CNT_TO_4500_US_SHIFT);
+
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);
@@ -1778,7 +1778,10 @@ 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;
}
@@ -1889,8 +1892,6 @@ static int vc4_hdmi_cec_init(struct vc4_hdmi *vc4_hdmi)
if (ret < 0)
goto err_remove_handlers;
- pm_runtime_put(&vc4_hdmi->pdev->dev);
-
return 0;
err_remove_handlers:
Commit 20b0dfa86bef0e80b41b0e5ac38b92f23b6f27f9 upstream. The original commit depended on a rework commit (724fc856c09e ("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: Michael Stapelberg <michael+drm@stapelberg.ch> Signed-off-by: Maxime Ripard <maxime@cerno.tech> --- drivers/gpu/drm/vc4/vc4_hdmi.c | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-)