From 8fcb5f027b3967cba11f941c459f9834ea3a7a35 Mon Sep 17 00:00:00 2001 From: Pawel Laszczak Date: Thu, 25 Aug 2022 08:22:07 +0200 Subject: [PATCH] usb: cdns3: fix incorrect handling TRB_SMM flag for ISOC transfer MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit d5dcc33677d7415c5f23b3c052f9e80cbab9ea4e ] The TRB_SMM flag indicates that DMA has completed the TD service with this TRB. Usually it’s a last TRB in TD. In case of ISOC transfer for bInterval > 1 each ISOC transfer contains more than one TD associated with usb request (one TD per ITP). In such case the TRB_SMM flag will be set in every TD and driver will recognize the end of transfer after processing the first TD with TRB_SMM. In result driver stops updating request->actual and returns incorrect actual length. To fix this issue driver additionally must check TRB_CHAIN which is not used for isochronous transfers. Fixes: 249f0a25e8be ("usb: cdns3: gadget: handle sg list use case at completion correctly") cc: Acked-by: Peter Chen Signed-off-by: Pawel Laszczak Link: https://lore.kernel.org/r/20220825062207.5824-1-pawell@cadence.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/usb/cdns3/gadget.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c index c6fc14b169da..d0d4de80680f 100644 --- a/drivers/usb/cdns3/gadget.c +++ b/drivers/usb/cdns3/gadget.c @@ -1531,7 +1531,8 @@ static void cdns3_transfer_completed(struct cdns3_device *priv_dev, TRB_LEN(le32_to_cpu(trb->length)); if (priv_req->num_of_trb > 1 && - le32_to_cpu(trb->control) & TRB_SMM) + le32_to_cpu(trb->control) & TRB_SMM && + le32_to_cpu(trb->control) & TRB_CHAIN) transfer_end = true; cdns3_ep_inc_deq(priv_ep);