Hi,
yfw <nh26223@xxxxxxxxx> writes:
>>> Bin Liu <b-liu@xxxxxx> writes:
>>>>>>>>> Does this mean the issue of isoc high bandwidth transfer was fixed by
>>>>>>>>> this patchset per your test?
>>>>>>>>
>>>>>>>> No, I couldn't get g_webcam to work yet.
>>>>>>>
>>>>>>> In mainline, g_webcam is broken with DWC3. Also these two patches don't
>>>>>>> fix the issue on v4.4.21.
>>>>>>
>>>>>> care to send tracepoint output? Best if you could cherry pick my latest
>>>>>> tracepoint changes so we have the best output possible.
>>>>>>
>>>>>> I have also built a branch with v4.4.21 + all dwc3 patches (except for
>>>>>> device properties and PCI stuff) which you could use for testing. If you
>>>>>> run with that, then I can get proper trace output and I can try to
>>>>>> figure out what's missing.
>>>>>>
>>>>>> Branch is here:
>>>>>>
>>>>>> git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git usb/v4.4.21+dwc3
>>>>>
>>>>> This branch does not generate the isoch traffic (on ep2in). ftrace
>>>>> attached (dwc3-g_webcam-v4.4.21+tp.ftrace).
>>>>>
>>>>> I also attached the ftrace log for v4.4.21 tag
>>>>> (dwc3-g_webcam-v4.4.21.ftrace) for comparison, which has ep2in isoch
>>>>> traffic, but only one transaction per SOF.
>>>>
>>>> Sorry, I didn't realize the ftrace file size is huge. Attached the
>>>> tarball here.
>>>
>>> looking at webcam.c, it'll set wMaxPacket correctly (to 0x1400) if you
>>> pass streaming_maxpacket=3072. So that's one thing.
>>>
>>> I'll look at this log with more detail tomorrow, though.
>>
>> here's a bug in composite.c because of a bug in usb_endpoint_maxp().
>>
>> diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
>> index 32176f779861..f6a7583ab6d1 100644
>> --- a/drivers/usb/gadget/composite.c
>> +++ b/drivers/usb/gadget/composite.c
>> @@ -197,7 +197,7 @@ int config_ep_by_speed(struct usb_gadget *g,
>>
>> ep_found:
>> /* commit results */
>> - _ep->maxpacket = usb_endpoint_maxp(chosen_desc);
>> + _ep->maxpacket = usb_endpoint_maxp(chosen_desc) & 0x7ff;
>
> uvc_video set the each request size (you could check function
> uvc_video_alloc_requests()) for uvc:
> req_size = video->ep->maxpacket
> * max_t(unsigned int, video->ep->maxburst, 1)
> * (video->ep->mult + 1);
>
>
> If we change the ep->maxpacket like this, uvc layer will only set the
> req size to 1024 (while it should be 3072 if we want to use high
> bindwidth isoc transfer).
it'll be 1024 * (mult + 1). Hmm, mult isn't set for highspeed isoc
endpoints. So here you go:
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index f6a7583ab6d1..03d9a7886922 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -201,7 +201,11 @@ int config_ep_by_speed(struct usb_gadget *g,
_ep->desc = chosen_desc;
_ep->comp_desc = NULL;
_ep->maxburst = 0;
- _ep->mult = 0;
+ _ep->mult = 1;
+
+ if (g->speed == USB_SPEED_HIGH && usb_endpoint_xfer_isoc(_ep->desc))
+ _ep->mult = usb_endpoint_isoc_maxp_mult(_ep->desc);
+
if (!want_comp_desc)
return 0;
@@ -218,7 +222,7 @@ int config_ep_by_speed(struct usb_gadget *g,
switch (usb_endpoint_type(_ep->desc)) {
case USB_ENDPOINT_XFER_ISOC:
/* mult: bits 1:0 of bmAttributes */
- _ep->mult = comp_desc->bmAttributes & 0x3;
+ _ep->mult = (comp_desc->bmAttributes & 0x3) + 1;
case USB_ENDPOINT_XFER_BULK:
case USB_ENDPOINT_XFER_INT:
_ep->maxburst = comp_desc->bMaxBurst + 1;
diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index 3d0d5d94a62f..0f01c04d7cbd 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -243,7 +243,7 @@ uvc_video_alloc_requests(struct uvc_video *video)
req_size = video->ep->maxpacket
* max_t(unsigned int, video->ep->maxburst, 1)
- * (video->ep->mult + 1);
+ * (video->ep->mult);
for (i = 0; i < UVC_NUM_REQUESTS; ++i) {
video->req_buffer[i] = kmalloc(req_size, GFP_KERNEL);
--
balbi
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