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FAILED: patch "[PATCH] usb: cdns3: fix incorrect handling TRB_SMM flag for ISOC" failed to apply to 5.10-stable tree

PATCH [email protected] 1 participant 1 message Sep 6, 2022

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The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From d5dcc33677d7415c5f23b3c052f9e80cbab9ea4e Mon Sep 17 00:00:00 2001
From: Pawel Laszczak <[email protected]>
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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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")
drivers/usb/cdns3/cdns3-gadget.c +2 -1
index d21b69997e75..4f11c311acaf 100644
@@ -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);