usb: dwc3: gadget: don't wrap around the TRB poll on non-ISOC

If we have a non-ISOC endpoint, we will not have a Link TRB
pointing to the beginning of the TRB pool. On such endpoints,
we don't want to let the driver wrap around the TRB pool
otherwise controller will hang waiting for a valid TRB.

Cc: stable@vger.kernel.org
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This commit is contained in:
Paul Zimmerman 2012-02-15 13:35:06 +02:00 committed by Felipe Balbi
parent 075cd14d2a
commit 8d62cd65d7

View file

@ -826,6 +826,7 @@ static void dwc3_prepare_trbs(struct dwc3_ep *dep, bool starting)
{
struct dwc3_request *req, *n;
u32 trbs_left;
u32 max;
unsigned int last_one = 0;
BUILD_BUG_ON_NOT_POWER_OF_2(DWC3_TRB_NUM);
@ -833,6 +834,13 @@ static void dwc3_prepare_trbs(struct dwc3_ep *dep, bool starting)
/* the first request must not be queued */
trbs_left = (dep->busy_slot - dep->free_slot) & DWC3_TRB_MASK;
/* Can't wrap around on a non-isoc EP since there's no link TRB */
if (!usb_endpoint_xfer_isoc(dep->desc)) {
max = DWC3_TRB_NUM - (dep->free_slot & DWC3_TRB_MASK);
if (trbs_left > max)
trbs_left = max;
}
/*
* If busy & slot are equal than it is either full or empty. If we are
* starting to process requests then we are empty. Otherwise we are