On 6/2/2016 5:26 AM, Felipe Balbi wrote: > > hi, > > Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> writes: >>> This reverts back to the original buggy behavior. This will fail when >>> a SET_INTERFACE occurs multiple times. >>> >>> You can run testusb to see the failure: >>> testusb -t 9 -c 5000 -s 2048 -a >> >> I came up with something else for this. It's still unstable and I need >> to debug further to figure out where we're wrong. But it seems to me >> that we're following databook down to the last comma with patch >> below. Note that we're partially reverting your original changes and >> adding some extra knowledge about current configuration and interface, >> then we only reassign transfer resources if those change. Care to have a >> look? > > here's a version that passes testusb and normal enumeration with g_zero > and g_mass_storage. After some experimenting, it seems like we should > always MODIFY resource allocation, unless we're doing a SetConfiguration > to the same configuration that is already chosen or a SetInterface to > the same interface/alt-setting pair that's already being used. This is > working for me. Can you test on your end too? Hi Felipe, You might be treading down a path we've already visited here :) It looks like this patch will still fail the case with multiple interfaces, with one or more having alt-settings. You will end up in a situation where multiple endpoints are assigned the same transfer resource which will cause failures. Unfortunately I don't have an easy test outside of our test environment that exposes this. You could try creating a composite device. Interface #1 having a single alt setting, interface #2 with multiple alt-settings. Start traffic to both interfaces, then start setting different alt-settings on interface #2. The problem is the databook does not cover this condition. The documentation will be fixed in 3.20a. Ravi Babu originally reported this and you can see discussion in this thread: http://marc.info/?l=linux-usb&m=145396682025403&w=2 Regards, John -- 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
