[v3,38/71] drm/vc4: hdmi: Rework power up

Commit Message

Maxime Ripard June 29, 2022, 12:34 p.m. UTC

The current code tries to handle the case where CONFIG_PM isn't selected
by first calling our runtime_resume implementation and then properly
report the power state to the runtime_pm core.

This allows to have a functionning device even if pm_runtime_get_*
functions are nops.

However, the device power state if CONFIG_PM is enabled is
RPM_SUSPENDED, and thus our vc4_hdmi_write() and vc4_hdmi_read() calls
in the runtime_pm hooks will now report a warning since the device might
not be properly powered.

Even more so, we need CONFIG_PM enabled since the previous RaspberryPi
have a power domain that needs to be powered up for the HDMI controller
to be usable.

The previous patch has created a dependency on CONFIG_PM, now we can
just assume it's there and only call pm_runtime_resume_and_get() to make
sure our device is powered in bind.

Signed-off-by: Maxime Ripard <[e-mail]>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

Comments

Maxime Ripard July 8, 2022, 9:42 a.m. UTC | #1

On Wed, 29 Jun 2022 14:34:37 +0200, Maxime Ripard wrote:
> The current code tries to handle the case where CONFIG_PM isn't selected
> by first calling our runtime_resume implementation and then properly
> report the power state to the runtime_pm core.
> 
> This allows to have a functionning device even if pm_runtime_get_*
> functions are nops.
> 
> [...]

Applied to drm/drm-misc (drm-misc-next).

Thanks!
Maxime

Patch

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 77e3ec52b175..73fb2f91c3e4 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -2971,18 +2971,16 @@  static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
 			vc4_hdmi->disable_4kp60 = true;
 	}
 
-	/*
-	 * We need to have the device powered up at this point to call
-	 * our reset hook and for the CEC init.
-	 */
-	ret = vc4_hdmi_runtime_resume(dev);
-	if (ret)
-		goto err_put_ddc;
-
-	pm_runtime_get_noresume(dev);
-	pm_runtime_set_active(dev);
 	pm_runtime_enable(dev);
 
+	/*
+	 *  We need to have the device powered up at this point to call
+	 *  our reset hook and for the CEC init.
+	 */
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret)
+		goto err_disable_runtime_pm;
+
 	if ((of_device_is_compatible(dev->of_node, "brcm,bcm2711-hdmi0") ||
 	     of_device_is_compatible(dev->of_node, "brcm,bcm2711-hdmi1")) &&
 	    HDMI_READ(HDMI_VID_CTL) & VC4_HD_VID_CTL_ENABLE) {
@@ -3027,6 +3025,7 @@  static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
 err_destroy_encoder:
 	drm_encoder_cleanup(encoder);
 	pm_runtime_put_sync(dev);
+err_disable_runtime_pm:
 	pm_runtime_disable(dev);
 err_put_ddc:
 	put_device(&vc4_hdmi->ddc->dev);