drm: Call drm_atomic_helper_shutdown() at shutdown/remove time for misc drivers

Based on grepping through the source code these drivers appear to be
missing a call to drm_atomic_helper_shutdown() at system shutdown time
and at driver remove (or unbind) time. Among other things, this means
that if a panel is in use that it won't be cleanly powered off at
system shutdown time.

The fact that we should call drm_atomic_helper_shutdown() in the case
of OS shutdown/restart and at driver remove (or unbind) time comes
straight out of the kernel doc "driver instance overview" in
drm_drv.c.

A few notes about these fixes:
- I confirmed that these drivers were all DRIVER_MODESET type drivers,
  which I believe makes this relevant.
- I confirmed that these drivers were all DRIVER_ATOMIC.
- When adding drm_atomic_helper_shutdown() to the remove/unbind path,
  I added it after drm_kms_helper_poll_fini() when the driver had
  it. This seemed to be what other drivers did. If
  drm_kms_helper_poll_fini() wasn't there I added it straight after
  drm_dev_unregister().
- This patch deals with drivers using the component model in similar
  ways as the patch ("drm: Call drm_atomic_helper_shutdown() at
  shutdown time for misc drivers")
- These fixes rely on the patch ("drm/atomic-helper:
  drm_atomic_helper_shutdown(NULL) should be a noop") to simplify
  shutdown.

Suggested-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> # tilcdc
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230901163944.RFT.5.I771eb4bd03d8772b19e7dcfaef3e2c167bce5846@changeid

1 files changed, 10 insertions, 1 deletions

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
index fe56beea3e93..8ebd7134ee21 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
@@ -175,6 +175,7 @@ static void tilcdc_fini(struct drm_device *dev)
 		drm_dev_unregister(dev);
 
 	drm_kms_helper_poll_fini(dev);
+	drm_atomic_helper_shutdown(dev);
 	tilcdc_irq_uninstall(dev);
 	drm_mode_config_cleanup(dev);
 
@@ -389,6 +390,7 @@ static int tilcdc_init(const struct drm_driver *ddrv, struct device *dev)
 
 init_failed:
 	tilcdc_fini(ddev);
+	platform_set_drvdata(pdev, NULL);
 
 	return ret;
 }
@@ -537,7 +539,8 @@ static void tilcdc_unbind(struct device *dev)
 	if (!ddev->dev_private)
 		return;
 
-	tilcdc_fini(dev_get_drvdata(dev));
+	tilcdc_fini(ddev);
+	dev_set_drvdata(dev, NULL);
 }
 
 static const struct component_master_ops tilcdc_comp_ops = {
@@ -582,6 +585,11 @@ static int tilcdc_pdev_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static void tilcdc_pdev_shutdown(struct platform_device *pdev)
+{
+	drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
+}
+
 static const struct of_device_id tilcdc_of_match[] = {
 		{ .compatible = "ti,am33xx-tilcdc", },
 		{ .compatible = "ti,da850-tilcdc", },
@@ -592,6 +600,7 @@ MODULE_DEVICE_TABLE(of, tilcdc_of_match);
 static struct platform_driver tilcdc_platform_driver = {
 	.probe      = tilcdc_pdev_probe,
 	.remove     = tilcdc_pdev_remove,
+	.shutdown   = tilcdc_pdev_shutdown,
 	.driver     = {
 		.name   = "tilcdc",
 		.pm     = pm_sleep_ptr(&tilcdc_pm_ops),