4.19-stable review patch. If anyone has any objections, please let me know.
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From: Douglas Anderson dianders@chromium.org
[ Upstream commit 16ac5b21b31b439f03cdf44c153c5f5af94fb3eb ]
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 mripard@kernel.org Reviewed-by: Maxime Ripard mripard@kernel.org Signed-off-by: Douglas Anderson dianders@chromium.org Tested-by: Marek Szyprowski m.szyprowski@samsung.com Reviewed-by: Marek Szyprowski m.szyprowski@samsung.com Signed-off-by: Inki Dae inki.dae@samsung.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/exynos/exynos_drm_drv.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c index b599f74692e5..db09e2055c86 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_drv.c +++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c @@ -410,6 +410,7 @@ static int exynos_drm_bind(struct device *dev) drm_release_iommu_mapping(drm); err_free_private: kfree(private); + dev_set_drvdata(dev, NULL); err_free_drm: drm_dev_put(drm);
@@ -424,6 +425,7 @@ static void exynos_drm_unbind(struct device *dev)
exynos_drm_fbdev_fini(drm); drm_kms_helper_poll_fini(drm); + drm_atomic_helper_shutdown(drm);
component_unbind_all(drm->dev, drm); drm_mode_config_cleanup(drm); @@ -461,9 +463,18 @@ static int exynos_drm_platform_remove(struct platform_device *pdev) return 0; }
+static void exynos_drm_platform_shutdown(struct platform_device *pdev) +{ + struct drm_device *drm = platform_get_drvdata(pdev); + + if (drm) + drm_atomic_helper_shutdown(drm); +} + static struct platform_driver exynos_drm_platform_driver = { .probe = exynos_drm_platform_probe, .remove = exynos_drm_platform_remove, + .shutdown = exynos_drm_platform_shutdown, .driver = { .name = "exynos-drm", .pm = &exynos_drm_pm_ops,