From 7cfc4ea78fc103ea51ecbacd9236abb5b1c490d2 Mon Sep 17 00:00:00 2001 From: Neil Armstrong Date: Fri, 30 Apr 2021 10:27:44 +0200 Subject: [PATCH 1/2] drm/meson: fix shutdown crash when component not probed When main component is not probed, by example when the dw-hdmi module is not loaded yet or in probe defer, the following crash appears on shutdown: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000038 ... pc : meson_drv_shutdown+0x24/0x50 lr : platform_drv_shutdown+0x20/0x30 ... Call trace: meson_drv_shutdown+0x24/0x50 platform_drv_shutdown+0x20/0x30 device_shutdown+0x158/0x360 kernel_restart_prepare+0x38/0x48 kernel_restart+0x18/0x68 __do_sys_reboot+0x224/0x250 __arm64_sys_reboot+0x24/0x30 ... Simply check if the priv struct has been allocated before using it. Fixes: fa0c16caf3d7 ("drm: meson_drv add shutdown function") Reported-by: Stefan Agner Signed-off-by: Neil Armstrong Tested-by: Martin Blumenstingl Reviewed-by: Martin Blumenstingl Link: https://patchwork.freedesktop.org/patch/msgid/20210430082744.3638743-1-narmstrong@baylibre.com --- drivers/gpu/drm/meson/meson_drv.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c index 453d8b4c5763..07fcd12dca16 100644 --- a/drivers/gpu/drm/meson/meson_drv.c +++ b/drivers/gpu/drm/meson/meson_drv.c @@ -485,11 +485,12 @@ static int meson_probe_remote(struct platform_device *pdev, static void meson_drv_shutdown(struct platform_device *pdev) { struct meson_drm *priv = dev_get_drvdata(&pdev->dev); - struct drm_device *drm = priv->drm; - DRM_DEBUG_DRIVER("\n"); - drm_kms_helper_poll_fini(drm); - drm_atomic_helper_shutdown(drm); + if (!priv) + return; + + drm_kms_helper_poll_fini(priv->drm); + drm_atomic_helper_shutdown(priv->drm); } static int meson_drv_probe(struct platform_device *pdev) From 35f819d218035ddfbc71e7cf62a4849231701e58 Mon Sep 17 00:00:00 2001 From: xinhui pan Date: Fri, 21 May 2021 16:31:12 +0800 Subject: [PATCH 2/2] drm/ttm: Skip swapout if ttm object is not populated MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Swapping a ttm object which has no backend pages makes no sense. Suggested-by: Christian König Signed-off-by: xinhui pan Reviewed-by: Christian König Link: https://patchwork.freedesktop.org/patch/msgid/20210521083112.33176-1-xinhui.pan@amd.com CC: stable@kernel.org Signed-off-by: Christian König --- drivers/gpu/drm/ttm/ttm_device.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c index 510e3e001dab..a1dcf7d55c90 100644 --- a/drivers/gpu/drm/ttm/ttm_device.c +++ b/drivers/gpu/drm/ttm/ttm_device.c @@ -145,7 +145,7 @@ int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx, list_for_each_entry(bo, &man->lru[j], lru) { uint32_t num_pages; - if (!bo->ttm || + if (!bo->ttm || !ttm_tt_is_populated(bo->ttm) || bo->ttm->page_flags & TTM_PAGE_FLAG_SG || bo->ttm->page_flags & TTM_PAGE_FLAG_SWAPPED) continue;