| Message ID | 20240728114200.75559-7-wahrenst@gmx.net |
|---|---|
| State | New |
| Headers | show |
| Series | ARM: bcm2835: Implement initial S2Idle for Raspberry Pi | expand |
On 7/28/24 08:41, Stefan Wahren wrote: > The commit 0f5251339eda ("drm/vc4: hdmi: Make sure the controller is > powered in detect") introduced the necessary power management handling > to avoid register access while controller is powered down. > Unfortunately it just print a warning if pm_runtime_resume_and_get() > fails and proceed anyway. > > This could happen during suspend to idle. So we must assume it is unsafe > to access the HDMI register. So bail out properly. > > Fixes: 0f5251339eda ("drm/vc4: hdmi: Make sure the controller is powered in detect") > Signed-off-by: Stefan Wahren <wahrenst@gmx.net> Reviewed-by: Maíra Canal <mcanal@igalia.com> Best Regards, - Maíra > --- > drivers/gpu/drm/vc4/vc4_hdmi.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c > index d57c4a5948c8..cb424604484f 100644 > --- a/drivers/gpu/drm/vc4/vc4_hdmi.c > +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c > @@ -429,6 +429,7 @@ static int vc4_hdmi_connector_detect_ctx(struct drm_connector *connector, > { > struct vc4_hdmi *vc4_hdmi = connector_to_vc4_hdmi(connector); > enum drm_connector_status status = connector_status_disconnected; > + int ret; > > /* > * NOTE: This function should really take vc4_hdmi->mutex, but > @@ -441,7 +442,12 @@ static int vc4_hdmi_connector_detect_ctx(struct drm_connector *connector, > * the lock for now. > */ > > - WARN_ON(pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev)); > + ret = pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev); > + if (ret) { > + drm_err_once(connector->dev, "Failed to retain HDMI power domain: %d\n", > + ret); > + return connector_status_unknown; > + } > > if (vc4_hdmi->hpd_gpio) { > if (gpiod_get_value_cansleep(vc4_hdmi->hpd_gpio)) > -- > 2.34.1 >
On Sun, 28 Jul 2024 13:41:50 +0200, Stefan Wahren wrote: > The commit 0f5251339eda ("drm/vc4: hdmi: Make sure the controller is > powered in detect") introduced the necessary power management handling > to avoid register access while controller is powered down. > Unfortunately it just print a warning if pm_runtime_resume_and_get() > fails and proceed anyway. > > [ ... ] Acked-by: Maxime Ripard <mripard@kernel.org> Thanks! Maxime
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index d57c4a5948c8..cb424604484f 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -429,6 +429,7 @@ static int vc4_hdmi_connector_detect_ctx(struct drm_connector *connector, { struct vc4_hdmi *vc4_hdmi = connector_to_vc4_hdmi(connector); enum drm_connector_status status = connector_status_disconnected; + int ret; /* * NOTE: This function should really take vc4_hdmi->mutex, but @@ -441,7 +442,12 @@ static int vc4_hdmi_connector_detect_ctx(struct drm_connector *connector, * the lock for now. */ - WARN_ON(pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev)); + ret = pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev); + if (ret) { + drm_err_once(connector->dev, "Failed to retain HDMI power domain: %d\n", + ret); + return connector_status_unknown; + } if (vc4_hdmi->hpd_gpio) { if (gpiod_get_value_cansleep(vc4_hdmi->hpd_gpio))
The commit 0f5251339eda ("drm/vc4: hdmi: Make sure the controller is powered in detect") introduced the necessary power management handling to avoid register access while controller is powered down. Unfortunately it just print a warning if pm_runtime_resume_and_get() fails and proceed anyway. This could happen during suspend to idle. So we must assume it is unsafe to access the HDMI register. So bail out properly. Fixes: 0f5251339eda ("drm/vc4: hdmi: Make sure the controller is powered in detect") Signed-off-by: Stefan Wahren <wahrenst@gmx.net> --- drivers/gpu/drm/vc4/vc4_hdmi.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) -- 2.34.1