[RFT PATCH 12/15] drm/gma500: Call drm_helper_force_disable_all() at shutdown/remove time

Douglas Anderson posted 15 patches 1 year ago
[RFT PATCH 12/15] drm/gma500: Call drm_helper_force_disable_all() at shutdown/remove time
Posted by Douglas Anderson 1 year ago
Based on grepping through the source code, this driver appears to be
missing a call to drm_atomic_helper_shutdown(), or in this case the
non-atomic equivalent drm_helper_force_disable_all(), at system
shutdown time and at driver remove time. This is important because
drm_helper_force_disable_all() will cause panels to get disabled
cleanly which may be important for their power sequencing. Future
changes will remove any custom powering off in individual panel
drivers so the DRM drivers need to start getting this right.

The fact that we should call drm_atomic_helper_shutdown(), or in this
case the non-atomic equivalent drm_helper_force_disable_all(), in the
case of OS shutdown/restart comes straight out of the kernel doc
"driver instance overview" in drm_drv.c.

Suggested-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
This commit is only compile-time tested.

 drivers/gpu/drm/gma500/psb_drv.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/gma500/psb_drv.c b/drivers/gpu/drm/gma500/psb_drv.c
index 8b64f61ffaf9..a5a399bbe8f5 100644
--- a/drivers/gpu/drm/gma500/psb_drv.c
+++ b/drivers/gpu/drm/gma500/psb_drv.c
@@ -20,6 +20,7 @@
 #include <acpi/video.h>
 
 #include <drm/drm.h>
+#include <drm/drm_crtc_helper.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_file.h>
 #include <drm/drm_ioctl.h>
@@ -485,6 +486,12 @@ static void psb_pci_remove(struct pci_dev *pdev)
 	struct drm_device *dev = pci_get_drvdata(pdev);
 
 	drm_dev_unregister(dev);
+	drm_helper_force_disable_all(dev);
+}
+
+static void psb_pci_shutdown(struct pci_dev *pdev)
+{
+	drm_helper_force_disable_all(pci_get_drvdata(pdev));
 }
 
 static DEFINE_RUNTIME_DEV_PM_OPS(psb_pm_ops, gma_power_suspend, gma_power_resume, NULL);
@@ -521,6 +528,7 @@ static struct pci_driver psb_pci_driver = {
 	.id_table = pciidlist,
 	.probe = psb_pci_probe,
 	.remove = psb_pci_remove,
+	.shutdown = psb_pci_shutdown,
 	.driver.pm = &psb_pm_ops,
 };
 
-- 
2.42.0.283.g2d96d420d3-goog
Re: [RFT PATCH 12/15] drm/gma500: Call drm_helper_force_disable_all() at shutdown/remove time
Posted by Maxime Ripard 1 year ago
On Fri, 1 Sep 2023 16:41:23 -0700, Douglas Anderson wrote:
> Based on grepping through the source code, this driver appears to be
> missing a call to drm_atomic_helper_shutdown(), or in this case the
> non-atomic equivalent drm_helper_force_disable_all(), at system
> shutdown time and at driver remove time. This is important because
> drm_helper_force_disable_all() will cause panels to get disabled
> 
> [ ... ]

Reviewed-by: Maxime Ripard <mripard@kernel.org>

Thanks!
Maxime