Based on grepping through the source code this driver appears to be missing a call to drm_atomic_helper_shutdown() at system shutdown time and at driver 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 this fix: - When adding drm_atomic_helper_shutdown() to the unbind path, I added it after drm_kms_helper_poll_fini() since that's when other drivers seemed to have it. - Technically with a previous patch, ("drm/atomic-helper: drm_atomic_helper_shutdown(NULL) should be a noop"), we don't actually need to check to see if our "drm" pointer is NULL before calling drm_atomic_helper_shutdown(). We'll leave the "if" test in, though, so that this patch can land without any dependencies. It could potentially be removed later. - This patch also makes sure to set the drvdata to NULL in the case of bind errors to make sure that shutdown can't access freed data. Suggested-by: Maxime Ripard <mrip...@kernel.org> Signed-off-by: Douglas Anderson <diand...@chromium.org> --- This commit is only compile-time tested. drivers/gpu/drm/imx/ipuv3/imx-drm-core.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c b/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c index 4a866ac60fff..4c8bc49758a7 100644 --- a/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c +++ b/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c @@ -257,6 +257,7 @@ static int imx_drm_bind(struct device *dev) drm_kms_helper_poll_fini(drm); component_unbind_all(drm->dev, drm); err_kms: + dev_set_drvdata(dev, NULL); drm_dev_put(drm); return ret; @@ -269,6 +270,7 @@ static void imx_drm_unbind(struct device *dev) drm_dev_unregister(drm); drm_kms_helper_poll_fini(drm); + drm_atomic_helper_shutdown(drm); component_unbind_all(drm->dev, drm); @@ -298,6 +300,14 @@ static int imx_drm_platform_remove(struct platform_device *pdev) return 0; } +static void imx_drm_platform_shutdown(struct platform_device *pdev) +{ + struct drm_device *drm = platform_get_drvdata(pdev); + + if (drm) + drm_atomic_helper_shutdown(platform_get_drvdata(pdev)); +} + #ifdef CONFIG_PM_SLEEP static int imx_drm_suspend(struct device *dev) { @@ -325,6 +335,7 @@ MODULE_DEVICE_TABLE(of, imx_drm_dt_ids); static struct platform_driver imx_drm_pdrv = { .probe = imx_drm_platform_probe, .remove = imx_drm_platform_remove, + .shutdown = imx_drm_platform_shutdown, .driver = { .name = "imx-drm", .pm = &imx_drm_pm_ops, -- 2.42.0.283.g2d96d420d3-goog