Hi, On Fri, Sep 18, 2015 at 04:53:09PM +0100, Felipe Tonello wrote: > Hi Balbi, > > On Fri, Sep 18, 2015 at 3:25 PM, Felipe Balbi <balbi@xxxxxx> wrote: > > On Fri, Sep 18, 2015 at 11:03:26AM +0100, Felipe Tonello wrote: > >> After some debugging, here is where I am: > >> > >> The crash trace is like this: > >> > >> (f_midi.c) > >> -> ALSA calls f_midi_in_trigger() > >> ->tasklet_hi_schedule(&midi->tasklet) > >> -> f_midi_transmit(midi, NULL) the NULL here causes the f_midi to > >> request a usb_request allocation, also it sets req->complete (which is > >> not been called? I am investigating this) > > > > ->complete() is called by the UDC when the request actually completes. > > The problem is that the udc driver is never calling it. I just realised that. > > (chipidea/udc.c) irqreturn_t udc_irq(struct ci_hdrc *ci) is not been > called after a f_midi_transmit(). Think here is the main problem. Any > ideas? have you looked at ci_irq() ? Look at how many return points it has. It's not inconceivable that it might be returning before calling ->udc_irq(). Now, if that's valid or not, it's for you decide. I don't even have this HW and can't help much more than this. > >> -> usb_ep_queue(ep, req, GFP_ATOMIC) > >> (chipidea/udc.c) > >> -> ep_queue(ep, req, gfp_flags) > >> -> _ep_queue(ep, req, gfp_flags) > >> -> _hardware_enqueue(hwep, hwreq) here is where it is crashing > >> -> add_td_to_list(hwep, hwreq, count) this guy returns > >> an error from dma_pool_alloc(), out of mem, which is not been checked > >> (I have a patch for this) > > > > oh, this probably part of the error. Care to send it ? > > Yes. It doesn't fix anything, but it prevents the kernel to panic. fair enough, and where's the patch ? > >> -> lastnode = list_entry(hwreq->tds.prev, struct > >> td_node, td) get last node (which is NULL) > >> -> lastnode->ptr->next = cpu_to_le32(TD_TERMINATE) > >> CRASH!!! lastnode->ptr is NULL > > > > if lastnode was initialized with list_entry(), it can't be > > NULL. You're missing something > > lastnode is not NULL, lastnode->ptr is NULL. (because of the > dma_pool_alloc, check add_td_to_list function). right, so you're running out of memory. Why are you running out of memory ? probably because ->udc_irq() is never called and, thus, you never free from coherent. Find reason for that and your problems will be gone, probably. > >> Any comments? > > > > yeah, continue debugging, what other information can you gather ? Does the > > problem go away if you add a ton of printks() around the code ? > > It doesn't change anything. ok, then it should be easy to reproduce. Wonder if this UDC has ever been tested with isochronous transfers at all. -- balbi
Attachment:
signature.asc
Description: Digital signature
