From: Paul Zimmerman <paulz@xxxxxxxxxxxx>
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.
Signed-off-by: Paul Zimmerman <paulz@xxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
---
Paul, are you happy with this fix instead ? I figured that
the same condition will happen on the scatterlist case too.
drivers/usb/dwc3/gadget.c | 13 +++++++++++--
1 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index cbe9bef..62e4793 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -672,8 +672,17 @@ static void dwc3_prepare_trbs(struct dwc3_ep *dep, bool starting)
BUILD_BUG_ON_NOT_POWER_OF_2(DWC3_TRB_NUM);
- /* 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) &&
+ (dep->free_slot & DWC3_TRB_MASK) == DWC3_TRB_MASK) {
+ trbs_left = 1;
+ } else {
+ /* the first request must not be queued */
+ trbs_left = (dep->busy_slot - dep->free_slot) & DWC3_TRB_MASK;
+ }
/*
* if busy & slot are equal than it is either full or empty. If we are
--
1.7.9
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