drm: virtio: reinstate drm_virtio_set_busid()

Before commit a325725 ("drm: Lobotomize set_busid nonsense for !pci drivers"), several DRM drivers for platform devices used to expose an explicit "drm_driver.set_busid" callback, invariably backed by drm_platform_set_busid(). Commit a325725 removed drm_platform_set_busid(), along with the referring .set_busid field initializations. This was justified because interchangeable functionality had been implemented in drm_dev_alloc() / drm_dev_init(), which DRM_IOCTL_SET_VERSION would rely on going forward. However, commit a325725 also removed drm_virtio_set_busid(), for which the same consolidation was not appropriate: this .set_busid callback had been implemented with drm_pci_set_busid(), and not drm_platform_set_busid(). The error regressed Xorg/xserver on QEMU's "virtio-vga" card; the drmGetBusid() function from libdrm would no longer return stable PCI identifiers like "pci:0000:00:02.0", but rather unstable platform ones like "virtio0". Reinstate drm_virtio_set_busid() with judicious use of git checkout -p a325725^ -- drivers/gpu/drm/virtio Cc: Daniel Vetter <[email protected]> Cc: Emil Velikov <[email protected]> Cc: Gerd Hoffmann <[email protected]> Cc: Gustavo Padovan <[email protected]> Cc: Hans de Goede <[email protected]> Cc: Joachim Frieben <[email protected]> Cc: [email protected] # v4.8 Reported-by: Joachim Frieben <[email protected]> Fixes: a325725 Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1366842 Signed-off-by: Laszlo Ersek <[email protected]> Reviewed-by: Emil Velikov <[email protected]> Signed-off-by: Dave Airlie <[email protected]>
lucamilanesio · Oct 4, 2016 · c2cbc38 · c2cbc38
1 parent 2adb29b
commit c2cbc38
Show file tree

Hide file tree

Showing 3 changed files with 12 additions and 0 deletions.
diff --git a/drivers/gpu/drm/virtio/virtgpu_drm_bus.c b/drivers/gpu/drm/virtio/virtgpu_drm_bus.c
@@ -28,6 +28,16 @@
 
 #include "virtgpu_drv.h"
 
+int drm_virtio_set_busid(struct drm_device *dev, struct drm_master *master)
+{
+	struct pci_dev *pdev = dev->pdev;
+
+	if (pdev) {
+		return drm_pci_set_busid(dev, master);
+	}
+	return 0;
+}
+
 static void virtio_pci_kick_out_firmware_fb(struct pci_dev *pci_dev)
 {
 	struct apertures_struct *ap;

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
@@ -117,6 +117,7 @@ static const struct file_operations virtio_gpu_driver_fops = {
 
 static struct drm_driver driver = {
 	.driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME | DRIVER_RENDER | DRIVER_ATOMIC,
+	.set_busid = drm_virtio_set_busid,
 	.load = virtio_gpu_driver_load,
 	.unload = virtio_gpu_driver_unload,
 	.open = virtio_gpu_driver_open,

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -49,6 +49,7 @@
 #define DRIVER_PATCHLEVEL 1
 
 /* virtgpu_drm_bus.c */
+int drm_virtio_set_busid(struct drm_device *dev, struct drm_master *master);
 int drm_virtio_init(struct drm_driver *driver, struct virtio_device *vdev);
 
 struct virtio_gpu_object {