There are a lot of common codes for preparing SG and linear TRBs.
Refactor them for easier read.
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
---
drivers/usb/dwc3/gadget.c | 129 ++++++++++++++------------------------
1 file changed, 48 insertions(+), 81 deletions(-)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 840d6e49f668..e6fa2d295439 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1094,6 +1094,47 @@ 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)
+ *
+ * Return the number of TRBs prepared.
+ */
+static int 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_trbs = 1;
+
+ if ((req->request.length && req->request.zero && !rem &&
+ !usb_endpoint_xfer_isoc(dep->endpoint.desc)) ||
+ (!req->direction && rem))
+ num_trbs++;
+
+ if (dwc3_calc_trbs_left(dep) < num_trbs)
+ return 0;
+
+ req->needs_extra_trb = num_trbs > 1;
+
+ /* Prepare a normal TRB */
+ if (req->direction || req->request.length)
+ dwc3_prepare_one_trb(dep, req, entry_length,
+ req->needs_extra_trb, node, false);
+
+ /* Prepare extra TRBs for ZLP and MPS OUT transfer alignment */
+ if ((!req->direction && !req->request.length) || req->needs_extra_trb)
+ dwc3_prepare_one_trb(dep, req,
+ req->direction ? 0 : maxp - rem,
+ false, 1, true);
+
+ return num_trbs;
+}
+
static int dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
struct dwc3_request *req)
{
@@ -1101,8 +1142,6 @@ static int dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
struct scatterlist *s;
int i;
unsigned int length = req->request.length;
- unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);
- unsigned int rem = length % maxp;
unsigned int remaining = req->request.num_mapped_sgs
- req->num_queued_sgs;
unsigned int num_trbs = req->num_trbs;
@@ -1116,7 +1155,7 @@ static int dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
for_each_sg(sg, s, remaining, i) {
unsigned int trb_length;
- unsigned int chain = true;
+ bool last_sg = false;
trb_length = min_t(unsigned int, length, sg_dma_len(s));
@@ -1130,45 +1169,16 @@ static int dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
* mapped sg.
*/
if ((i == remaining - 1) || !length)
- chain = false;
+ last_sg = true;
if (!dwc3_calc_trbs_left(dep))
break;
- if (rem && usb_endpoint_dir_out(dep->endpoint.desc) && !chain) {
- /* prepare normal TRB */
- if (req->request.length) {
- if (dwc3_calc_trbs_left(dep) < 2)
- goto out;
-
- req->needs_extra_trb = true;
- dwc3_prepare_one_trb(dep, req, trb_length,
- true, i, false);
- }
-
- /* Now prepare one extra TRB to align transfer size */
- dwc3_prepare_one_trb(dep, req, maxp - rem,
- false, 1, true);
- } else if (req->request.zero && req->request.length &&
- !usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
- !rem && !chain) {
-
- if (dwc3_calc_trbs_left(dep) < 2)
+ if (last_sg) {
+ if (!dwc3_prepare_last_sg(dep, req, trb_length, i))
goto out;
-
- req->needs_extra_trb = true;
-
- /* Prepare normal TRB */
- dwc3_prepare_one_trb(dep, req, trb_length,
- true, i, false);
-
- /* Prepare one extra TRB to handle ZLP */
- dwc3_prepare_one_trb(dep, req,
- req->direction ? 0 : maxp,
- false, 1, true);
} else {
- dwc3_prepare_one_trb(dep, req, trb_length,
- chain, i, false);
+ dwc3_prepare_one_trb(dep, req, trb_length, 1, i, false);
}
/*
@@ -1178,7 +1188,7 @@ static int 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++;
@@ -1224,50 +1234,7 @@ static int dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
static int 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;
- unsigned int num_trbs = req->num_trbs;
-
- if (!dwc3_calc_trbs_left(dep))
- goto out;
-
- if ((!length || rem) && usb_endpoint_dir_out(dep->endpoint.desc)) {
- /* prepare normal TRB */
- if (req->request.length) {
- if (dwc3_calc_trbs_left(dep) < 2)
- goto out;
-
- req->needs_extra_trb = true;
- dwc3_prepare_one_trb(dep, req, length, true, 0, false);
- }
-
- /* Now prepare one extra TRB to align transfer size */
- dwc3_prepare_one_trb(dep, req, maxp - rem, false, 1, true);
- } else if (req->request.zero && req->request.length &&
- !usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
- (IS_ALIGNED(req->request.length, maxp))) {
-
- if (dwc3_calc_trbs_left(dep) < 2)
- goto out;
-
- req->needs_extra_trb = true;
-
- /* prepare normal TRB */
- dwc3_prepare_one_trb(dep, req, length, true, 0, false);
-
- /* Prepare one extra TRB to handle ZLP */
- dwc3_prepare_one_trb(dep, req, req->direction ? 0 : maxp,
- false, 1, true);
- } else {
- if (!dwc3_calc_trbs_left(dep))
- goto out;
-
- dwc3_prepare_one_trb(dep, req, length, false, 0, false);
- }
-
-out:
- return req->num_trbs - num_trbs;
+ return dwc3_prepare_last_sg(dep, req, req->request.length, 0);
}
/*
--
2.28.0
