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, 0 deletions

diff --git a/drivers/gpu/drm/vboxvideo/vbox_drv.c b/drivers/gpu/drm/vboxvideo/vbox_drv.c
index 4fee15c97c34..047b95812334 100644
--- a/drivers/gpu/drm/vboxvideo/vbox_drv.c
+++ b/drivers/gpu/drm/vboxvideo/vbox_drv.c
@@ -12,6 +12,7 @@
 #include <linux/vt_kern.h>
 
 #include <drm/drm_aperture.h>
+#include <drm/drm_atomic_helper.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_fbdev_generic.h>
 #include <drm/drm_file.h>
@@ -97,11 +98,19 @@ static void vbox_pci_remove(struct pci_dev *pdev)
 	struct vbox_private *vbox = pci_get_drvdata(pdev);
 
 	drm_dev_unregister(&vbox->ddev);
+	drm_atomic_helper_shutdown(&vbox->ddev);
 	vbox_irq_fini(vbox);
 	vbox_mode_fini(vbox);
 	vbox_hw_fini(vbox);
 }
 
+static void vbox_pci_shutdown(struct pci_dev *pdev)
+{
+	struct vbox_private *vbox = pci_get_drvdata(pdev);
+
+	drm_atomic_helper_shutdown(&vbox->ddev);
+}
+
 static int vbox_pm_suspend(struct device *dev)
 {
 	struct vbox_private *vbox = dev_get_drvdata(dev);
@@ -165,6 +174,7 @@ static struct pci_driver vbox_pci_driver = {
 	.id_table = pciidlist,
 	.probe = vbox_pci_probe,
 	.remove = vbox_pci_remove,
+	.shutdown = vbox_pci_shutdown,
 	.driver.pm = pm_sleep_ptr(&vbox_pm_ops),
 };