The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
Possible dependencies:
1301c7b9f7ef ("usb: cdns3: remove fetched trb from cache before dequeuing")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 1301c7b9f7efad2f11ef924e317c18ebd714fc9a Mon Sep 17 00:00:00 2001 From: Pawel Laszczak pawell@cadence.com Date: Tue, 15 Nov 2022 05:00:39 -0500 Subject: [PATCH] usb: cdns3: remove fetched trb from cache before dequeuing
After doorbell DMA fetches the TRB. If during dequeuing request driver changes NORMAL TRB to LINK TRB but doesn't delete it from controller cache then controller will handle cached TRB and packet can be lost.
The example scenario for this issue looks like: 1. queue request - set doorbell 2. dequeue request 3. send OUT data packet from host 4. Device will accept this packet which is unexpected 5. queue new request - set doorbell 6. Device lost the expected packet.
By setting DFLUSH controller clears DRDY bit and stop DMA transfer.
Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver") cc: stable@vger.kernel.org Signed-off-by: Pawel Laszczak pawell@cadence.com Acked-by: Peter Chen peter.chen@kernel.org Link: https://lore.kernel.org/r/20221115100039.441295-1-pawell@cadence.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c index 5adcb349718c..ccfaebca6faa 100644 --- a/drivers/usb/cdns3/cdns3-gadget.c +++ b/drivers/usb/cdns3/cdns3-gadget.c @@ -2614,6 +2614,7 @@ int cdns3_gadget_ep_dequeue(struct usb_ep *ep, u8 req_on_hw_ring = 0; unsigned long flags; int ret = 0; + int val;
if (!ep || !request || !ep->desc) return -EINVAL; @@ -2649,6 +2650,13 @@ int cdns3_gadget_ep_dequeue(struct usb_ep *ep,
/* Update ring only if removed request is on pending_req_list list */ if (req_on_hw_ring && link_trb) { + /* Stop DMA */ + writel(EP_CMD_DFLUSH, &priv_dev->regs->ep_cmd); + + /* wait for DFLUSH cleared */ + readl_poll_timeout_atomic(&priv_dev->regs->ep_cmd, val, + !(val & EP_CMD_DFLUSH), 1, 1000); + link_trb->buffer = cpu_to_le32(TRB_BUFFER(priv_ep->trb_pool_dma + ((priv_req->end_trb + 1) * TRB_SIZE))); link_trb->control = cpu_to_le32((le32_to_cpu(link_trb->control) & TRB_CYCLE) | @@ -2660,6 +2668,10 @@ int cdns3_gadget_ep_dequeue(struct usb_ep *ep,
cdns3_gadget_giveback(priv_ep, priv_req, -ECONNRESET);
+ req = cdns3_next_request(&priv_ep->pending_req_list); + if (req) + cdns3_rearm_transfer(priv_ep, 1); + not_found: spin_unlock_irqrestore(&priv_dev->lock, flags); return ret;