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: stable@vger.kernel.org Signed-off-by: Pawel Laszczak pawell@cadence.com --- drivers/usb/cdns3/cdns3-gadget.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c index fa8263951e63..a6618a922c61 100644 --- a/drivers/usb/cdns3/cdns3-gadget.c +++ b/drivers/usb/cdns3/cdns3-gadget.c @@ -1529,7 +1529,8 @@ 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);