From: Pawel Laszczak pawell@cadence.com
commit d5dcc33677d7415c5f23b3c052f9e80cbab9ea4e upstream.
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 Acked-by: Peter Chen peter.chen@kernel.org Signed-off-by: Pawel Laszczak pawell@cadence.com Link: https://lore.kernel.org/r/20220825062207.5824-1-pawell@cadence.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/cdns3/cdns3-gadget.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/usb/cdns3/cdns3-gadget.c +++ b/drivers/usb/cdns3/cdns3-gadget.c @@ -1530,7 +1530,8 @@ static void cdns3_transfer_completed(str 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);