This is a note to let you know that I've just added the patch titled
usb: cdns3: gadget: toggle cycle bit before reset endpoint
to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 4bf2dd65135a2d7fe202f7c10d65b51bcf645ac6 Mon Sep 17 00:00:00 2001
From: Peter Chen peter.chen@nxp.com Date: Wed, 19 Feb 2020 22:14:55 +0800 Subject: usb: cdns3: gadget: toggle cycle bit before reset endpoint
If there are TRBs pending during reset endpoint operation, the DMA will advance after reset operation, but it isn't expected, since the data is not yet available (For OUT, the data is not yet available). After the data is ready, there won't be any interrupt since the EP_TRADDR already points to next TRB entry and doorbell is not set.
To fix it, it toggles cycle bit before reset operation, and restores it after reset, it could avoid unexpected DMA advance due to cycle bit is for software during the endpoint reset operation.
Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver") Signed-off-by: Peter Chen peter.chen@nxp.com Cc: stable stable@vger.kernel.org Link: https://lore.kernel.org/r/20200219141455.23257-3-peter.chen@nxp.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/cdns3/gadget.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c index 1d8a2af35bb0..3574dbb09366 100644 --- a/drivers/usb/cdns3/gadget.c +++ b/drivers/usb/cdns3/gadget.c @@ -2595,11 +2595,21 @@ int __cdns3_gadget_ep_clear_halt(struct cdns3_endpoint *priv_ep) { struct cdns3_device *priv_dev = priv_ep->cdns3_dev; struct usb_request *request; + struct cdns3_request *priv_req; + struct cdns3_trb *trb = NULL; int ret; int val;
trace_cdns3_halt(priv_ep, 0, 0);
+ request = cdns3_next_request(&priv_ep->pending_req_list); + if (request) { + priv_req = to_cdns3_request(request); + trb = priv_req->trb; + if (trb) + trb->control = trb->control ^ TRB_CYCLE; + } + writel(EP_CMD_CSTALL | EP_CMD_EPRST, &priv_dev->regs->ep_cmd);
/* wait for EPRST cleared */ @@ -2610,10 +2620,11 @@ int __cdns3_gadget_ep_clear_halt(struct cdns3_endpoint *priv_ep)
priv_ep->flags &= ~(EP_STALLED | EP_STALL_PENDING);
- request = cdns3_next_request(&priv_ep->pending_req_list); - - if (request) + if (request) { + if (trb) + trb->control = trb->control ^ TRB_CYCLE; cdns3_rearm_transfer(priv_ep, 1); + }
cdns3_start_all_request(priv_dev, priv_ep); return ret;