[PATCH v3] usb: dwc3: gadget: Simplify TRB reclaim logic by removing redundant 'chain' argument

SCHNEIDER Johannes
2025-06-25T07:53:20Z

Now that the TRB reclaim logic always inspects the TRB's CHN (Chain) bit
directly to determine whether a TRB is part of a chain, the explicit
'chain' parameter passed into dwc3_gadget_ep_reclaim_completed_trb()
is no longer necessary.

This cleanup simplifies the reclaim code by avoiding duplication of
chain state tracking, and makes the reclaim logic rely entirely on the
hardware descriptor flags — which are already present and accurate at
this stage.

No functional changes intended.

Signed-off-by: Johannes Schneider <johannes.schneider@leica-geosystems.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
---
v3: no changes, re-submission as single patch
v2: no changes to the patch, "faulty" re-submission
v1: initial submission as part of a series
Link: https://lore.kernel.org/lkml/AM8PR06MB7521CFF1CD8A93622A537EEDBC78A@AM8PR06MB7521.eurprd06.prod.outlook.com/

drivers/usb/dwc3/gadget.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 99fbd29d8f46..a4a2bf273f94 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -3497,7 +3497,7 @@ static void dwc3_gadget_free_endpoints(struct dwc3 *dwc)

static int dwc3_gadget_ep_reclaim_completed_trb(struct dwc3_ep *dep,
struct dwc3_request *req, struct dwc3_trb *trb,
- const struct dwc3_event_depevt *event, int status, int chain)
+ const struct dwc3_event_depevt *event, int status)
{
unsigned int count;

@@ -3549,7 +3549,8 @@ static int dwc3_gadget_ep_reclaim_completed_trb(struct dwc3_ep *dep,
if ((trb->ctrl & DWC3_TRB_CTRL_HWO) && status != -ESHUTDOWN)
return 1;

- if (event->status & DEPEVT_STATUS_SHORT && !chain)
+ if (event->status & DEPEVT_STATUS_SHORT &&
+ !(trb->ctrl & DWC3_TRB_CTRL_CHN))
return 1;

if ((trb->ctrl & DWC3_TRB_CTRL_ISP_IMI) &&
@@ -3576,8 +3577,7 @@ static int dwc3_gadget_ep_reclaim_trb_sg(struct dwc3_ep *dep,
trb = &dep->trb_pool[dep->trb_dequeue];

ret = dwc3_gadget_ep_reclaim_completed_trb(dep, req,
- trb, event, status,
- !!(trb->ctrl & DWC3_TRB_CTRL_CHN));
+ trb, event, status);
if (ret)
break;
}
--
2.43.0