Hi Felipe, > >> On 04/02/2014 10:47 AM, Peter Chen wrote: > >>> We have historic problem that the gadget will not work if the gadget > >>> is build-in and the udc driver is defered probe due to some > >>> resources are not ready. Below links are related to this problem. > >>> > >>> http://marc.info/?l=linux-usb&m=139380872501745&w=2 > >>> http://marc.info/?l=linux-usb&m=137991612311893&w=2 > >>> http://marc.info/?l=linux-usb&m=137706435611447&w=2 > >>> > >>> This patch saves pointer of usb_gadget_driver when the udc is not > >>> ready, and redo usb_gadget_probe_driver when the udc is ready This > >>> method may not be good enough, but we need to find a way to fix this > >>> problem, so I post this RFC to see if to see comments, someone may > >>> have a better solution:) > >>> > >> > >> I have sent patch fixing this problem few weeks ago: > >> http://www.spinics.net/lists/linux-usb/msg102795.html > >> > > > > Our idea is the same, but your patch is better than me. > > Felipe queued this patch or not? > > > > If it is not, you may need to send v2 that return -ENODEV for not find > > udc to see if he has further comments, let's try to fix this problem > > at mainline asap. > > > > Returning -ENODEV doesn't make sense. There is no way to find out if any > UDC driver is present in system before it will be registered. So you > can't know, when you should return -ENODEV. > > If we really want to return -ENODEV, it will need to modify all UDC > drivers. They can notify udc-core before returning -EPROBE_DEFER that > they will register in the future, so gadget drivers can be added to > driver_list. In another case we can return -ENODEV. > What do you think about this solution? We still have unsolved problem with deferred probe in UDC drivers, so there is real need for some fixes. Best regards Robert Baldyga Samsung R&D Institute Poland -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
