I never received any replies to this message. Should the patch I suggested be merged? Alan Stern On Tue, 12 Jul 2016, Alan Stern wrote: > On Sat, 9 Jul 2016, Mauro Carvalho Chehab wrote: > > > C/C linux-usb Mailing list: > > > > > > Em Wed, 18 May 2016 08:52:28 -0600 > > Wade Berrier <wberrier@xxxxxxxxx> escreveu: > > ... > > > > > That message above links to some other threads describing the issue. > > > > Here's a post with a patch that supposedly works: > > > > > > > > http://www.gossamer-threads.com/lists/mythtv/users/587930 > > > > > > > > No idea if that's the "correct" way to fix this. > > > > > > > > I'll be trying that out and then report back... > > > > > > Indeed, this patch does fix the issue: > > > > > > ---------------------- > > > > > > diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c > > > index 31ccdcc..03321d4 100644 > > > --- a/drivers/usb/core/config.c > > > +++ b/drivers/usb/core/config.c > > > @@ -247,7 +247,7 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum, > > > /* For low-speed, 10 ms is the official minimum. > > > * But some "overclocked" devices might want faster > > > * polling so we'll allow it. */ > > > - n = 32; > > > + n = 10; > > > break; > > > } > > > } else if (usb_endpoint_xfer_isoc(d)) { > > > > > > > > > ---------------------- > > > > > > Is this change appropriate to be pushed upstream? Where to go from > > > here? > > > > This issue is at the USB core. So, it should be reported to the > > linux-usb mailing list. > > > > The people there should help about how to proceed to get this > > fixed upstream. > > Here's a proper version of that patch. If this is okay, it can be > merged. > > Alan Stern > > > > Index: usb-4.x/drivers/usb/core/config.c > =================================================================== > --- usb-4.x.orig/drivers/usb/core/config.c > +++ usb-4.x/drivers/usb/core/config.c > @@ -213,8 +213,10 @@ static int usb_parse_endpoint(struct dev > memcpy(&endpoint->desc, d, n); > INIT_LIST_HEAD(&endpoint->urb_list); > > - /* Fix up bInterval values outside the legal range. Use 32 ms if no > - * proper value can be guessed. */ > + /* > + * Fix up bInterval values outside the legal range. > + * Use 10 or 8 ms if no proper value can be guessed. > + */ > i = 0; /* i = min, j = max, n = default */ > j = 255; > if (usb_endpoint_xfer_int(d)) { > @@ -223,13 +225,15 @@ static int usb_parse_endpoint(struct dev > case USB_SPEED_SUPER_PLUS: > case USB_SPEED_SUPER: > case USB_SPEED_HIGH: > - /* Many device manufacturers are using full-speed > + /* > + * Many device manufacturers are using full-speed > * bInterval values in high-speed interrupt endpoint > * descriptors. Try to fix those and fall back to a > - * 32 ms default value otherwise. */ > + * 8 ms default value otherwise. > + */ > n = fls(d->bInterval*8); > if (n == 0) > - n = 9; /* 32 ms = 2^(9-1) uframes */ > + n = 7; /* 8 ms = 2^(7-1) uframes */ > j = 16; > > /* > @@ -247,7 +251,7 @@ static int usb_parse_endpoint(struct dev > /* For low-speed, 10 ms is the official minimum. > * But some "overclocked" devices might want faster > * polling so we'll allow it. */ > - n = 32; > + n = 10; > break; > } > } else if (usb_endpoint_xfer_isoc(d)) { > @@ -255,10 +259,10 @@ static int usb_parse_endpoint(struct dev > j = 16; > switch (to_usb_device(ddev)->speed) { > case USB_SPEED_HIGH: > - n = 9; /* 32 ms = 2^(9-1) uframes */ > + n = 7; /* 8 ms = 2^(7-1) uframes */ > break; > default: /* USB_SPEED_FULL */ > - n = 6; /* 32 ms = 2^(6-1) frames */ > + n = 4; /* 8 ms = 2^(4-1) frames */ > break; > } > } -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
