On 2018-04-30 17:24, Daniel Vetter wrote: > On Fri, Apr 27, 2018 at 12:31:38AM +0200, Peter Rosin wrote: >> The .owner will be handy to have around. >> >> Signed-off-by: Peter Rosin <p...@axentia.se> >> --- >> drivers/gpu/drm/drm_bridge.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c >> index 9f023bd84d56..a038da696802 100644 >> --- a/drivers/gpu/drm/drm_bridge.c >> +++ b/drivers/gpu/drm/drm_bridge.c >> @@ -115,6 +115,9 @@ int drm_bridge_attach(struct drm_encoder *encoder, >> struct drm_bridge *bridge, >> if (!encoder || !bridge) >> return -EINVAL; >> >> + if (WARN_ON(!bridge->owner)) >> + return -EINVAL; > > I think conceptually this is checked at the wrong place, and I think also > misnamed > a bit. The ->owner is essentially the struct device (and its associated > driver) that provides the drm_bridge. As such it should be filled out > already at drm_bridge_add() time, and I think the check should be in > there. For driver-internal bridges it might make sense to also check this > here, not sure. Or just require all bridges get added.
The reason for the position is that while I originally had the WARN in drm_bridge_add, I found that quite a few bridges never call drm_bridge_add. So I moved it. Other options are to start requiring all bridge suppliers to call drm_bridge_add or to have the WARN in both function. Too me, it would make sense to require all bridge suppliers to call drm_bridge_add, as that enables other init stuff later, when needed. But that is a hairy patch to get right, and is probably best left as a separate series. > Wrt the name, I think we should call this pdev or something. ->owner > usually means the module owner. I think in other subsystems ->dev is used, > but in drm we use ->dev for the drm_device pointer, so totally different > thing. pdev = physical device is the best I came up with. Better > suggestions very much welcome. pdev is about as problematic as owner. To me it reads "platform device". And dev for a drm_device is also somewhat problematic, and I think that drm would have been better, but dev for drm_device is probably quite common. But one way to go is to rename the current dev to drm, so that dev is freed up for the owner/supplier device. But that is a tedious patch to write (I don't do the cocci thing). Other suggestions I can think of: odev for owner device, sdev for supplier device or just plain supplier. Cheers, Peter > -Daniel > >> + >> if (previous && (!previous->dev || previous->encoder != encoder)) >> return -EINVAL; >> >> -- >> 2.11.0 >> >> _______________________________________________ >> dri-devel mailing list >> dri-de...@lists.freedesktop.org >> https://lists.freedesktop.org/mailman/listinfo/dri-devel >