There are a lot of common codes for preparing SG and linear TRBs. Let's
refactor them for easier read. No functional change here.
Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx>
---
Changes in v2:
- Remove unused variables rem and maxp
drivers/usb/dwc3/gadget.c | 178 ++++++++++++++------------------------
1 file changed, 67 insertions(+), 111 deletions(-)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index c2a0f64f8d1e..f929810580bf 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1088,6 +1088,65 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
stream_id, short_not_ok, no_interrupt, is_last);
}
+/**
+ * dwc3_prepare_last_sg - prepare TRBs for the last SG entry
+ * @dep: The endpoint that the request belongs to
+ * @req: The request to prepare
+ * @entry_length: The last SG entry size
+ * @node: Indicates whether this is not the first entry (for isoc only)
+ */
+static void dwc3_prepare_last_sg(struct dwc3_ep *dep,
+ struct dwc3_request *req,
+ unsigned int entry_length,
+ unsigned int node)
+{
+ unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);
+ unsigned int rem = req->request.length % maxp;
+ unsigned int num_extra_trbs = 0;
+ unsigned int i;
+ bool do_zlp = false;
+
+ if (!usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
+ req->request.zero && req->request.length && !rem) {
+ num_extra_trbs++;
+ do_zlp = true;
+ }
+
+ if (!req->direction && (!req->request.length || rem || do_zlp))
+ num_extra_trbs++;
+
+ if (num_extra_trbs > 0)
+ req->needs_extra_trb = true;
+
+ /* Prepare a normal TRB */
+ dwc3_prepare_one_trb(dep, req, entry_length, req->needs_extra_trb, node);
+
+ /* Prepare extra TRBs for ZLP and MPS OUT transfer alignment */
+ for (i = 0; i < num_extra_trbs; i++) {
+ struct dwc3 *dwc = dep->dwc;
+ struct dwc3_trb *trb;
+ unsigned int extra_trb_length;
+ bool chain = true;
+
+ if (do_zlp && !i)
+ extra_trb_length = 0;
+ else
+ extra_trb_length = maxp - rem;
+
+ if (i == num_extra_trbs - 1)
+ chain = false;
+
+ trb = &dep->trb_pool[dep->trb_enqueue];
+ req->num_trbs++;
+ __dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr,
+ extra_trb_length, chain, 1,
+ req->request.stream_id,
+ req->request.short_not_ok,
+ req->request.no_interrupt,
+ req->request.is_last);
+ }
+}
+
static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
struct dwc3_request *req)
{
@@ -1106,10 +1165,8 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
length -= sg_dma_len(s);
for_each_sg(sg, s, remaining, i) {
- unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);
- unsigned int rem = length % maxp;
unsigned int trb_length;
- unsigned chain = true;
+ bool last_sg = false;
trb_length = min_t(unsigned int, length, sg_dma_len(s));
@@ -1123,60 +1180,12 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
* mapped sg.
*/
if ((i == remaining - 1) || !length)
- chain = false;
+ last_sg = true;
- if (rem && usb_endpoint_dir_out(dep->endpoint.desc) && !chain) {
- struct dwc3 *dwc = dep->dwc;
- struct dwc3_trb *trb;
-
- req->needs_extra_trb = true;
-
- /* prepare normal TRB */
- dwc3_prepare_one_trb(dep, req, trb_length, true, i);
-
- /* Now prepare one extra TRB to align transfer size */
- trb = &dep->trb_pool[dep->trb_enqueue];
- req->num_trbs++;
- __dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr,
- maxp - rem, false, 1,
- req->request.stream_id,
- req->request.short_not_ok,
- req->request.no_interrupt,
- req->request.is_last);
- } else if (req->request.zero && req->request.length &&
- !usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
- !rem && !chain) {
- struct dwc3 *dwc = dep->dwc;
- struct dwc3_trb *trb;
-
- req->needs_extra_trb = true;
-
- /* Prepare normal TRB */
- dwc3_prepare_one_trb(dep, req, trb_length, true, i);
-
- /* Prepare one extra TRB to handle ZLP */
- trb = &dep->trb_pool[dep->trb_enqueue];
- req->num_trbs++;
- __dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, 0,
- !req->direction, 1,
- req->request.stream_id,
- req->request.short_not_ok,
- req->request.no_interrupt,
- req->request.is_last);
-
- /* Prepare one more TRB to handle MPS alignment */
- if (!req->direction) {
- trb = &dep->trb_pool[dep->trb_enqueue];
- req->num_trbs++;
- __dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, maxp,
- false, 1, req->request.stream_id,
- req->request.short_not_ok,
- req->request.no_interrupt,
- req->request.is_last);
- }
- } else {
- dwc3_prepare_one_trb(dep, req, trb_length, chain, i);
- }
+ if (last_sg)
+ dwc3_prepare_last_sg(dep, req, trb_length, i);
+ else
+ dwc3_prepare_one_trb(dep, req, trb_length, 1, i);
/*
* There can be a situation where all sgs in sglist are not
@@ -1185,7 +1194,7 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
* we have free trbs we can continue queuing from where we
* previously stopped
*/
- if (chain)
+ if (!last_sg)
req->start_sg = sg_next(s);
req->num_queued_sgs++;
@@ -1208,60 +1217,7 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
struct dwc3_request *req)
{
- unsigned int length = req->request.length;
- unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);
- unsigned int rem = length % maxp;
-
- if ((!length || rem) && usb_endpoint_dir_out(dep->endpoint.desc)) {
- struct dwc3 *dwc = dep->dwc;
- struct dwc3_trb *trb;
-
- req->needs_extra_trb = true;
-
- /* prepare normal TRB */
- dwc3_prepare_one_trb(dep, req, length, true, 0);
-
- /* Now prepare one extra TRB to align transfer size */
- trb = &dep->trb_pool[dep->trb_enqueue];
- req->num_trbs++;
- __dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, maxp - rem,
- false, 1, req->request.stream_id,
- req->request.short_not_ok,
- req->request.no_interrupt,
- req->request.is_last);
- } else if (req->request.zero && req->request.length &&
- !usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
- (IS_ALIGNED(req->request.length, maxp))) {
- struct dwc3 *dwc = dep->dwc;
- struct dwc3_trb *trb;
-
- req->needs_extra_trb = true;
-
- /* prepare normal TRB */
- dwc3_prepare_one_trb(dep, req, length, true, 0);
-
- /* Prepare one extra TRB to handle ZLP */
- trb = &dep->trb_pool[dep->trb_enqueue];
- req->num_trbs++;
- __dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, 0,
- !req->direction, 1, req->request.stream_id,
- req->request.short_not_ok,
- req->request.no_interrupt,
- req->request.is_last);
-
- /* Prepare one more TRB to handle MPS alignment for OUT */
- if (!req->direction) {
- trb = &dep->trb_pool[dep->trb_enqueue];
- req->num_trbs++;
- __dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, maxp,
- false, 1, req->request.stream_id,
- req->request.short_not_ok,
- req->request.no_interrupt,
- req->request.is_last);
- }
- } else {
- dwc3_prepare_one_trb(dep, req, length, false, 0);
- }
+ dwc3_prepare_last_sg(dep, req, req->request.length, 0);
}
/*
--
2.28.0
