From bc8e94c902d8b5a24d6b31963fc26058b54986ef Mon Sep 17 00:00:00 2001 From: Artur Rojek Date: Wed, 13 Sep 2023 17:00:58 +0200 Subject: [PATCH] usb: gadget: atmel: fix transfer of queued requests In the existing implementation, multiple requests queued up on an endpoint are subject to getting evicted without transmission. For both control and bulk endpoints, their respective logic found in usba_control_irq()/usba_ep_irq() guarantees that TX FIFO is empty before data is sent out, and that request_complete() gets called once the transaction has been finished. At this point however, if any additional requests are found on the endpoint queue, they will be processed by submit_next_request(), which makes no checks against the above conditions, trashing data on a busy FIFO and neglecting completion handlers. Fix the above issues by removing the calls to submit_next_request(), and thus forcing the pending requests to be processed on the next pass of the respective endpoint logic. While at it, remove a DBG message, as that branch becomes part of regular flow. This restores mass storage mode operation on Microchip ATSAMA5D27 SoC. Signed-off-by: Artur Rojek --- drivers/usb/gadget/atmel_usba_udc.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) diff --git a/drivers/usb/gadget/atmel_usba_udc.c b/drivers/usb/gadget/atmel_usba_udc.c index f16731c8eb..4c420747b0 100644 --- a/drivers/usb/gadget/atmel_usba_udc.c +++ b/drivers/usb/gadget/atmel_usba_udc.c @@ -58,13 +58,9 @@ static void submit_request(struct usba_ep *ep, struct usba_request *req) req->submitted = 1; next_fifo_transaction(ep, req); - if (req->last_transaction) { - usba_ep_writel(ep, CTL_DIS, USBA_TX_PK_RDY); - usba_ep_writel(ep, CTL_ENB, USBA_TX_COMPLETE); - } else { + if (ep_is_control(ep)) usba_ep_writel(ep, CTL_DIS, USBA_TX_COMPLETE); - usba_ep_writel(ep, CTL_ENB, USBA_TX_PK_RDY); - } + usba_ep_writel(ep, CTL_ENB, USBA_TX_PK_RDY); } static void submit_next_request(struct usba_ep *ep) @@ -890,7 +886,6 @@ restart: if (req) { list_del_init(&req->queue); request_complete(ep, req, 0); - submit_next_request(ep); } usba_ep_writel(ep, CTL_DIS, USBA_TX_COMPLETE); ep->state = WAIT_FOR_SETUP; @@ -1037,7 +1032,6 @@ static void usba_ep_irq(struct usba_udc *udc, struct usba_ep *ep) DBG(DBG_BUS, "%s: TX PK ready\n", ep->ep.name); if (list_empty(&ep->queue)) { - DBG(DBG_INT, "ep_irq: queue empty\n"); usba_ep_writel(ep, CTL_DIS, USBA_TX_PK_RDY); return; } @@ -1051,7 +1045,6 @@ static void usba_ep_irq(struct usba_udc *udc, struct usba_ep *ep) if (req->last_transaction) { list_del_init(&req->queue); - submit_next_request(ep); request_complete(ep, req, 0); } -- 2.39.5