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| author | Dmitry Osipenko <dmitry.osipenko@collabora.com> | 2023-03-06 17:39:16 +0100 |
|---|---|---|
| committer | Dmitry Osipenko <dmitry.osipenko@collabora.com> | 2023-03-06 18:32:17 +0100 |
| commit | aad9729ec0e009440ac8c1a4be2204e4d3c08977 (patch) | |
| tree | f4f82bbd6e2ac1a5cf4f14b1570978c3d0e2a6e1 /drivers/gpu/drm/virtio | |
| parent | drm/meson/meson_venc: Relax the supported mode checks (diff) | |
| download | linux-aad9729ec0e009440ac8c1a4be2204e4d3c08977.tar.xz linux-aad9729ec0e009440ac8c1a4be2204e4d3c08977.zip | |
drm/virtio: Fix handling CONFIG_DRM_VIRTIO_GPU_KMS option
VirtIO-GPU got a new config option for disabling KMS. There were two
problems left unnoticed during review when the new option was added:
1. The IS_ENABLED(CONFIG_DRM_VIRTIO_GPU_KMS) check in the code was
inverted, hence KMS was disabled when it should be enabled and vice versa.
2. The disabled KMS crashed kernel with a NULL dereference in
drm_kms_helper_hotplug_event(), which shall not be invoked with a
disabled KMS.
Fix the inverted config option check in the code and skip handling the
VIRTIO_GPU_EVENT_DISPLAY sent by host when KMS is disabled in guest to fix
the crash.
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Fixes: 72122c69d717 ("drm/virtio: Add option to disable KMS support")
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230306163916.1595961-1-dmitry.osipenko@collabora.com
Diffstat (limited to 'drivers/gpu/drm/virtio')
| -rw-r--r-- | drivers/gpu/drm/virtio/virtgpu_kms.c | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/drivers/gpu/drm/virtio/virtgpu_kms.c b/drivers/gpu/drm/virtio/virtgpu_kms.c index 02e5c18c2c75..5a3b5aaed1f3 100644 --- a/drivers/gpu/drm/virtio/virtgpu_kms.c +++ b/drivers/gpu/drm/virtio/virtgpu_kms.c @@ -43,11 +43,13 @@ static void virtio_gpu_config_changed_work_func(struct work_struct *work) virtio_cread_le(vgdev->vdev, struct virtio_gpu_config, events_read, &events_read); if (events_read & VIRTIO_GPU_EVENT_DISPLAY) { - if (vgdev->has_edid) - virtio_gpu_cmd_get_edids(vgdev); - virtio_gpu_cmd_get_display_info(vgdev); - virtio_gpu_notify(vgdev); - drm_helper_hpd_irq_event(vgdev->ddev); + if (vgdev->num_scanouts) { + if (vgdev->has_edid) + virtio_gpu_cmd_get_edids(vgdev); + virtio_gpu_cmd_get_display_info(vgdev); + virtio_gpu_notify(vgdev); + drm_helper_hpd_irq_event(vgdev->ddev); + } events_clear |= VIRTIO_GPU_EVENT_DISPLAY; } virtio_cwrite_le(vgdev->vdev, struct virtio_gpu_config, @@ -224,7 +226,7 @@ int virtio_gpu_init(struct virtio_device *vdev, struct drm_device *dev) vgdev->num_scanouts = min_t(uint32_t, num_scanouts, VIRTIO_GPU_MAX_SCANOUTS); - if (IS_ENABLED(CONFIG_DRM_VIRTIO_GPU_KMS) || !vgdev->num_scanouts) { + if (!IS_ENABLED(CONFIG_DRM_VIRTIO_GPU_KMS) || !vgdev->num_scanouts) { DRM_INFO("KMS disabled\n"); vgdev->num_scanouts = 0; vgdev->has_edid = false; @@ -247,9 +249,9 @@ int virtio_gpu_init(struct virtio_device *vdev, struct drm_device *dev) if (num_capsets) virtio_gpu_get_capsets(vgdev, num_capsets); - if (vgdev->has_edid) - virtio_gpu_cmd_get_edids(vgdev); if (vgdev->num_scanouts) { + if (vgdev->has_edid) + virtio_gpu_cmd_get_edids(vgdev); virtio_gpu_cmd_get_display_info(vgdev); virtio_gpu_notify(vgdev); wait_event_timeout(vgdev->resp_wq, !vgdev->display_info_pending, |