From: Thierry Reding treding@nvidia.com
The only reason why struct drm_bus is still around is because the SETVERSION IOCTL calls a bus specific .set_busid() function. This commit provides a fallback implementation if a device either doesn't have a bus associated with it or if it doesn't implement .set_busid(). The bus ID will be set to the device's name as returned by dev_name().
This can be useful to create DRM devices directly in drivers using the drm_dev_alloc() and drm_dev_register() functions rather than going through the bus-specific implementations, with the goal of eventually getting rid of drm_bus entirely.
Signed-off-by: Thierry Reding treding@nvidia.com --- drivers/gpu/drm/drm_ioctl.c | 26 +++++++++++++++++++++++--- 1 file changed, 23 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c index 93a42040bedb..d27134a94d69 100644 --- a/drivers/gpu/drm/drm_ioctl.c +++ b/drivers/gpu/drm/drm_ioctl.c @@ -122,6 +122,19 @@ err: return ret; }
+static int __drm_set_busid(struct drm_device *dev, struct drm_master *master) +{ + const char *name = dev_name(dev->dev); + + master->unique = kstrdup(name, GFP_KERNEL); + if (!master->unique) + return -ENOMEM; + + master->unique_len = strlen(name); + + return 0; +} + static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv) { struct drm_master *master = file_priv->master; @@ -130,9 +143,16 @@ static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv) if (master->unique != NULL) drm_unset_busid(dev, master);
- ret = dev->driver->bus->set_busid(dev, master); - if (ret) - goto err; + if (dev->driver->bus && dev->driver->bus->set_busid) { + ret = dev->driver->bus->set_busid(dev, master); + if (ret) + goto err; + } else { + ret = __drm_set_busid(dev, master); + if (ret) + goto err; + } + return 0; err: drm_unset_busid(dev, master);