Hi On Thu, Jan 23, 2014 at 9:52 AM, Daniel Vetter <daniel.vetter@xxxxxxxx> wrote: > Driver modules really don't have much business frobbing around with > this: Splitting up modeset resources (if we ever get around to enable > this for real) should be something purely controlled and managed by > the drm core in a driver-agnostic fashion. As usual imx disagrees, but > that's due to the convoluted setup sequence. Russell King is working > on a proper fix for that, so this patch needs to wait for those to > land to avoid breaking imx. I tried working on "modeset-object splitting" as part of the DRM-Master rework, but that's all really racy and we'd break current user-space. For instance the object-indices (compared to object-IDs) need to be constant, but with our current object-lists, removing an object will change indices (thus breaking possible_crtcs/encoders). There are ways to make that work, but it'd require huge drm_crtc.c changes. And I also think our locking doesn't provide for that. Furthermore, resource-retrieval is not atomic (we need multiple ioctls: GetResources, GetCrtc, ...) so if we change the objects in between, we may break running apps in a subtle way. So I'm all for making object-lists immutable after drm_dev_register() was called. Imo, hardware should wait for all sub-devices to be present and then call drm_dev_register(). Once the first sub-device is removed, you call drm_dev_unregister(). And I think that's what Russel's compound-device infrastructure does by hiding the sub-devices in a compound device. If there's ever hardware that truly supports sub-device hotplugging, we can support that by adding a DRM-ClientCap like 3D modes. But as I understand, the current hardware is still a single piece of hardware which just might get probed via different buses and thus is not an atomic entity. So the device is still hotplugged as a whole, we just don't get the events through a single path. Thanks David > > Cc: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> > Cc: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx> > --- > drivers/gpu/drm/drm_crtc.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c > index cf134540b675..98084413a842 100644 > --- a/drivers/gpu/drm/drm_crtc.c > +++ b/drivers/gpu/drm/drm_crtc.c > @@ -1264,7 +1264,6 @@ int drm_mode_group_init_legacy_group(struct drm_device *dev, > > return 0; > } > -EXPORT_SYMBOL(drm_mode_group_init_legacy_group); > > /** > * drm_crtc_convert_to_umode - convert a drm_display_mode into a modeinfo > -- > 1.8.5.2 > > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/dri-devel _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
