From d5dcc33677d7415c5f23b3c052f9e80cbab9ea4e Mon Sep 17 00:00:00 2001
From: Pawel Laszczak <pawell@cadence.com>
Date: Thu, 25 Aug 2022 08:22:07 +0200
Subject: [PATCH] usb: cdns3: fix incorrect handling TRB_SMM flag for ISOC transfer
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Git-commit: d5dcc33677d7415c5f23b3c052f9e80cbab9ea4e
Patch-mainline: v6.0-rc4
References: git-fixes
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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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 d21b69997e75..4f11c311acaf 100644
--- a/drivers/usb/cdns3/cdns3-gadget.c
+++ b/drivers/usb/cdns3/cdns3-gadget.c
@@ -1530,7 +1530,8 @@ 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);
--
2.35.3