usb: ci_udc: pre-allocate ep0 req

Allocate ep0's USB request object when the UDC driver is probed. This
solves a couple of issues in the current code:

a) A request object always exists for ep0. Prior to this patch, if setup
transactions arrived in an unexpected order, handle_setup() would need
to reply to a setup transaction before any ep0 usb_req was created.

This issue was introduced in commit 2813006fecda "usb: ci_udc: allow
multiple buffer allocs per ep."

b) handle_ep_complete no longer /has/ to queue the ep0 request again
after every single request completion. This is currently required, since
handle_setup() assumes it can find some request object in ep0's request
queue. This patch doesn't actually stop handle_ep_complete() from always
requeueing the request, but the next patch will.

Signed-off-by: Stephen Warren <swarren@nvidia.com>

diff --git a/drivers/usb/gadget/ci_udc.c b/drivers/usb/gadget/ci_udc.c
index 77f8c9ef7f0f6fe3dfa5f82cce67367cf1ee5c98..03ad23164fe131e80967283acc1f4ec9952e703e 100644 (file)
--- a/drivers/usb/gadget/ci_udc.c
+++ b/drivers/usb/gadget/ci_udc.c
@@ -198,8 +198,14 @@ static void ci_invalidate_qtd(int ep_num)
 static struct usb_request *
 ci_ep_alloc_request(struct usb_ep *ep, unsigned int gfp_flags)
 {
+       struct ci_ep *ci_ep = container_of(ep, struct ci_ep, ep);
+       int num;
        struct ci_req *ci_req;
 
+       num = ci_ep->desc->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
+       if (num == 0 && controller.ep0_req)
+               return &controller.ep0_req->req;
+
        ci_req = memalign(ARCH_DMA_MINALIGN, sizeof(*ci_req));
        if (!ci_req)
                return NULL;
@@ -207,6 +213,9 @@ ci_ep_alloc_request(struct usb_ep *ep, unsigned int gfp_flags)
        INIT_LIST_HEAD(&ci_req->queue);
        ci_req->b_buf = 0;
 
+       if (num == 0)
+               controller.ep0_req = ci_req;
+
        return &ci_req->req;
 }
 
@@ -471,7 +480,7 @@ static void handle_setup(void)
        int num, in, _num, _in, i;
        char *buf;
 
-       ci_req = list_first_entry(&ci_ep->queue, struct ci_req, queue);
+       ci_req = controller.ep0_req;
        req = &ci_req->req;
        head = ci_get_qh(0, 0); /* EP0 OUT */
 
@@ -780,6 +789,12 @@ static int ci_udc_probe(void)
                              &controller.gadget.ep_list);
        }
 
+       ci_ep_alloc_request(&controller.ep[0].ep, 0);
+       if (!controller.ep0_req) {
+               free(controller.epts);
+               return -ENOMEM;
+       }
+
        return 0;
 }
 

diff --git a/drivers/usb/gadget/ci_udc.h b/drivers/usb/gadget/ci_udc.h
index 23cff56d7ec92d7653ece4611db27cfa8c5ce7a7..7d76af84f03756fd37df39e462a9edf7ba7ca053 100644 (file)
--- a/drivers/usb/gadget/ci_udc.h
+++ b/drivers/usb/gadget/ci_udc.h
@@ -97,6 +97,7 @@ struct ci_ep {
 
 struct ci_drv {
        struct usb_gadget               gadget;
+       struct ci_req                   *ep0_req;
        struct usb_gadget_driver        *driver;
        struct ehci_ctrl                *ctrl;
        struct ept_queue_head           *epts;