On Thu, May 20, 2021 at 3:14 PM Geoffrey D. Bennett g@b4.vu wrote:
On Tue, May 18, 2021 at 06:41:45PM -0300, Geraldo Nascimento wrote: [...]
Myself I'd hook printk()'s to both ehci_hcd and xhci_hcd to print every possible variable involved and see if there's any relevant mismatches. Oh and watch with the printk()'s what libusb seems to be doing, too.
When you subscribe to linux-usb you *may* want to Cc: Greg Kroah-Hartman with your discoveries so far, he's the USB Subsystem Maintainer and the best one to help you track this down.
Thanks for the pointers!
It turns out that usb_sndctrlpipe() is not short for "USB sound control pipe".
diff --git a/sound/usb/mixer_scarlett_gen2.c b/sound/usb/mixer_scarlett_gen2.c index 560c2ade829d..dcff3e3a49f3 100644 --- a/sound/usb/mixer_scarlett_gen2.c +++ b/sound/usb/mixer_scarlett_gen2.c @@ -635,7 +635,7 @@ static int scarlett2_usb( /* send a second message to get the response */
err = snd_usb_ctl_msg(mixer->chip->dev,
usb_sndctrlpipe(mixer->chip->dev, 0),
usb_rcvctrlpipe(mixer->chip->dev, 0), SCARLETT2_USB_VENDOR_SPECIFIC_CMD_RESP, USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN, 0,I'll properly submit the patch once I've got confirmation from someone else that this fixes the issue.
Good, I also think the correct pipe to use together with USB_DIR_IN is indeed usb_rcvctrlpipe().
Thanks again, Geoffrey.