usb: dwc3: gadget: align transfers to wMaxPacketSize

Instead of passing quirk_ep_out_aligned_size, we can use one extra TRB
to align transfer to wMaxPacketSize.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 9b4b79ae0beb4df05c57ee651d142a79493cde6d..2b9e4ca3c932e5691376dc9504d870804cccc695 100644 (file)
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -725,6 +725,7 @@ struct dwc3_hwparams {
  * @epnum: endpoint number to which this request refers
  * @trb: pointer to struct dwc3_trb
  * @trb_dma: DMA address of @trb
+ * @unaligned: true for OUT endpoints with length not divisible by maxp
  * @direction: IN or OUT direction flag
  * @mapped: true when request has been dma-mapped
  * @queued: true when request has been queued to HW
@@ -741,6 +742,7 @@ struct dwc3_request {
        struct dwc3_trb         *trb;
        dma_addr_t              trb_dma;
 
+       unsigned                unaligned:1;
        unsigned                direction:1;
        unsigned                mapped:1;
        unsigned                started:1;

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 653251751e3843cbc2b4364f90584f31cade05f2..6faf484e5dfcebb3f0cf19f734658e2d9301ac8d 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -992,12 +992,33 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
        int             i;
 
        for_each_sg(sg, s, req->num_pending_sgs, i) {
+               unsigned int length = req->request.length;
+               unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);
+               unsigned int rem = length % maxp;
                unsigned chain = true;
 
                if (sg_is_last(s))
                        chain = false;
 
-               dwc3_prepare_one_trb(dep, req, chain, i);
+               if (rem && usb_endpoint_dir_out(dep->endpoint.desc) && !chain) {
+                       struct dwc3     *dwc = dep->dwc;
+                       struct dwc3_trb *trb;
+
+                       req->unaligned = true;
+
+                       /* prepare normal TRB */
+                       dwc3_prepare_one_trb(dep, req, true, i);
+
+                       /* Now prepare one extra TRB to align transfer size */
+                       trb = &dep->trb_pool[dep->trb_enqueue];
+                       __dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr,
+                                       maxp - rem, false, 0,
+                                       req->request.stream_id,
+                                       req->request.short_not_ok,
+                                       req->request.no_interrupt);
+               } else {
+                       dwc3_prepare_one_trb(dep, req, chain, i);
+               }
 
                if (!dwc3_calc_trbs_left(dep))
                        break;
@@ -1007,7 +1028,28 @@ 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)
 {
-       dwc3_prepare_one_trb(dep, req, false, 0);
+       unsigned int length = req->request.length;
+       unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);
+       unsigned int rem = length % maxp;
+
+       if (rem && usb_endpoint_dir_out(dep->endpoint.desc)) {
+               struct dwc3     *dwc = dep->dwc;
+               struct dwc3_trb *trb;
+
+               req->unaligned = true;
+
+               /* prepare normal TRB */
+               dwc3_prepare_one_trb(dep, req, true, 0);
+
+               /* Now prepare one extra TRB to align transfer size */
+               trb = &dep->trb_pool[dep->trb_enqueue];
+               __dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, maxp - rem,
+                               false, 0, req->request.stream_id,
+                               req->request.short_not_ok,
+                               req->request.no_interrupt);
+       } else {
+               dwc3_prepare_one_trb(dep, req, false, 0);
+       }
 }
 
 /*
@@ -2031,6 +2073,16 @@ static int __dwc3_cleanup_done_trbs(struct dwc3 *dwc, struct dwc3_ep *dep,
        if (chain && (trb->ctrl & DWC3_TRB_CTRL_HWO))
                trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
 
+       /*
+        * If we're dealing with unaligned size OUT transfer, we will be left
+        * with one TRB pending in the ring. We need to manually clear HWO bit
+        * from that TRB.
+        */
+       if (req->unaligned && (trb->ctrl & DWC3_TRB_CTRL_HWO)) {
+               trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
+               return 1;
+       }
+
        if ((trb->ctrl & DWC3_TRB_CTRL_HWO) && status != -ESHUTDOWN)
                return 1;
 
@@ -2120,6 +2172,13 @@ static int dwc3_cleanup_done_reqs(struct dwc3 *dwc, struct dwc3_ep *dep,
                                        event, status, chain);
                }
 
+               if (req->unaligned) {
+                       trb = &dep->trb_pool[dep->trb_dequeue];
+                       ret = __dwc3_cleanup_done_trbs(dwc, dep, req, trb,
+                                       event, status, false);
+                       req->unaligned = false;
+               }
+
                req->request.actual = length - req->remaining;
 
                if ((req->request.actual < length) && req->num_pending_sgs)
@@ -3058,12 +3117,6 @@ int dwc3_gadget_init(struct dwc3 *dwc)
 
        dwc->gadget.max_speed           = dwc->maximum_speed;
 
-       /*
-        * Per databook, DWC3 needs buffer size to be aligned to MaxPacketSize
-        * on ep out.
-        */
-       dwc->gadget.quirk_ep_out_aligned_size = true;
-
        /*
         * REVISIT: Here we should clear all pending IRQs to be
         * sure we're starting from a well known location.