Hi, Dan Scally <dan.scally@xxxxxxxxxxxxxxxx> writes: > I'm having an issue with DWC3 which I'm hoping you might be able to shed > light on. I'm using the UVC gadget function to stream video from an > imx8mp platform, which works just fine. Once I have stopped streaming > however and after some time has passed (the exact duration seems to vary > quite a lot from 1-2 minutes to 15+ mins) I get a kernel warning like so: As Greg mentioned, please add Thinh, the new maintainer, to the loop. > [ 737.996842] configfs-gadget gadget.0: uvc: uvc_function_disable() > [ 738.519582] configfs-gadget gadget.0: uvc: uvc_function_set_alt(0, 0) > [ 738.526060] configfs-gadget gadget.0: uvc: reset UVC interrupt endpoint > [ 738.532713] ------------[ cut here ]------------ > [ 738.537683] dwc3 38100000.usb: No resource for ep1in > [ 738.542712] WARNING: CPU: 0 PID: 645 at drivers/usb/dwc3/gadget.c:384 > dwc3_send_gadget_ep_cmd+0x478/0x580 > [ 738.552314] Modules linked in: > [ 738.555402] CPU: 0 PID: 645 Comm: irq/208-dwc3 Not tainted > 5.19.0-00034-gf017ce943b32 #82 > [ 738.563601] Hardware name: Polyhex Debix Model A i.MX8MPlus board (DT) > [ 738.570145] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS > BTYPE=--) > [ 738.577128] pc : dwc3_send_gadget_ep_cmd+0x478/0x580 > [ 738.582116] lr : dwc3_send_gadget_ep_cmd+0x478/0x580 > [ 738.587102] sp : ffffffc00c3c39e0 > [ 738.590433] x29: ffffffc00c3c39e0 x28: 0000000000031006 x27: > 00000000ffffffea > [ 738.597618] x26: 0000000000000006 x25: ffffff8004f32880 x24: > ffffffc00c3c3abc > [ 738.604801] x23: 0000000000000406 x22: ffffffffffff3f00 x21: > ffffffffffff3f0c > [ 738.611984] x20: ffffff8003872600 x19: 0000000000000001 x18: > ffffffffffffffff > [ 738.619166] x17: 000000000000001c x16: 00000000c99c42a5 x15: > ffffffc08c3c36b7 > [ 738.626347] x14: 0000000000000000 x13: 6e6931706520726f x12: > 6620656372756f73 > [ 738.633528] x11: 00000000000c02a7 x10: ffffffc009af1ac0 x9 : > ffffffc0080c42bc > [ 738.640710] x8 : 00000000ffffefff x7 : ffffffc009af1ac0 x6 : > 0000000000000000 > [ 738.647891] x5 : ffffff807fb2eb08 x4 : 0000000000000000 x3 : > 0000000000000027 > [ 738.655072] x2 : 0000000000000000 x1 : 0000000000000000 x0 : > ffffff80158a8000 > [ 738.662255] Call trace: > [ 738.664721] dwc3_send_gadget_ep_cmd+0x478/0x580 > [ 738.669362] __dwc3_gadget_ep_enable+0x4f4/0x714 > [ 738.674004] dwc3_gadget_ep_enable+0x6c/0x15c > [ 738.678382] usb_ep_enable+0x4c/0x1bc > [ 738.682067] uvc_function_set_alt+0xcc/0x264 > [ 738.686362] composite_setup+0x7ec/0x195c > [ 738.690395] configfs_composite_setup+0x90/0xc0 > [ 738.694950] dwc3_ep0_interrupt+0x834/0x9e0 > [ 738.699156] dwc3_thread_interrupt+0x994/0xd70 > [ 738.703624] irq_thread_fn+0x38/0xa4 > [ 738.707221] irq_thread+0x184/0x230 > [ 738.710733] kthread+0x118/0x120 > [ 738.713981] ret_from_fork+0x10/0x20 > [ 738.717582] irq event stamp: 41021 > [ 738.720998] hardirqs last enabled at (41019): [<ffffffc008082858>] > finish_task_switch.isra.0+0xe8/0x264 > [ 738.730501] hardirqs last disabled at (41021): [<ffffffc008f15058>] > _raw_spin_lock_irqsave+0xc4/0x170 > [ 738.739747] softirqs last enabled at (41014): [<ffffffc008a25b90>] > dwc3_thread_interrupt+0x1c0/0xd70 > [ 738.748988] softirqs last disabled at (41020): [<ffffffc008a259dc>] > dwc3_thread_interrupt+0xc/0xd70 > > > ep1in in this instance refers to a Status Interrupt Endpoint under the > UVC specification, which is being "reset" by uvc_function_set_alt() > against the VideoControl interface (meaning a call to usb_ep_disable() > followed by usb_ep_enable(), see [1]). The isochronous endpoint that > data is streamed across is treated similarly in the same function (when > called for the VideoStreaming interface) and never seems to show the > same warning and as far as I can tell the operation ought to be safe, so > I'm struggling to see anything in the f_uvc code that's misbehaving to > cause the problem. I wondered if you might be able to take a look at the > trace and regdump of the dwc3 (which was taken immediately after the > warning is thrown) and see if that sheds any light on what might be > going on? Best way forward is to collect dwc3 trace points, so we can see what the HW is doing. For details, see [1]. [1] https://kernel.org/doc/html/latest/driver-api/usb/dwc3.html#reporting-bugs -- balbi
Attachment:
signature.asc
Description: PGP signature
