Commit 56b1ee72 authored Dec 15, 2015 by Jack Pham

usb: dwc3: Fix handling of ISOC start transfer



A transfer on an isochronous endpoint needs special handling if
it was queued after the interval has expired. This case is
checked by testing bit 13 when a START TRANSFER command fails,
and returning -EAGAIN to indicate to the caller to end the transfer
and try again on the next interval. However, the test itself is
obscured because the function will simply return -EINVAL if any
of bits 15:12 are set. Fix this by correctly reordering the checks.

This was caused by an incorrect merge conflict resolution between
commit 561ba0fe ("usb: dwc3: gadget: return error if command
sent to DEPCMD register fails") and commit ef1891fa ("USB:
dwc3: Fix issues in isochronous endpoint handling").

Change-Id: Id1ec2c030efb94bac435172d7f030e68c7e10535
Signed-off-by: Jack Pham <jackp@codeaurora.org>

parent 7427cd00

drivers/usb/dwc3/gadget.c

+3 −5

Original line number	Diff line number	Diff line
		@@ -350,9 +350,6 @@ int dwc3_send_gadget_ep_cmd(struct dwc3 *dwc, unsigned ep,
		dev_vdbg(dwc->dev, "Command Complete --> %d\n",
		DWC3_DEPCMD_STATUS(reg));

		if (DWC3_DEPCMD_STATUS(reg))
		return -EINVAL;

		/* SW issues START TRANSFER command to isochronous ep
		* with future frame interval. If future interval time
		* has already passed when core recieves command, core
		@@ -361,7 +358,8 @@ int dwc3_send_gadget_ep_cmd(struct dwc3 *dwc, unsigned ep,
		*/
		if (reg & 0x2000)
		return -EAGAIN;
		else
		else if (DWC3_DEPCMD_STATUS(reg))
		return -EINVAL;
		return 0;
		}