4.8-stable review patch. If anyone has any objections, please let me know.
------------------ From: Laszlo Ersek <[email protected]> commit c2cbc38b9715bd8318062e600668fc30e5a3fbfa upstream. Before commit a325725633c2 ("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 a325725633c2 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 a325725633c2 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 a325725633c2^ -- 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]> Reported-by: Joachim Frieben <[email protected]> Fixes: a325725633c26aa66ab940f762a6b0778edf76c0 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]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/gpu/drm/virtio/virtgpu_drm_bus.c | 10 ++++++++++ drivers/gpu/drm/virtio/virtgpu_drv.c | 1 + drivers/gpu/drm/virtio/virtgpu_drv.h | 1 + 3 files changed, 12 insertions(+) --- a/drivers/gpu/drm/virtio/virtgpu_drm_bus.c +++ b/drivers/gpu/drm/virtio/virtgpu_drm_bus.c @@ -27,6 +27,16 @@ #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; --- 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 virt 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, --- 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 {
