FAILED: patch "[PATCH] xhci: handle isoc Babble and Buffer Overrun events properly" failed to apply to 5.10-stable tree

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]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 7c4650ded49e5b88929ecbbb631efb8b0838e811
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2024021308-hardness-undercook-6840@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:

7c4650ded49e ("xhci: handle isoc Babble and Buffer Overrun events properly")

thanks,

greg k-h

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

From 7c4650ded49e5b88929ecbbb631efb8b0838e811 Mon Sep 17 00:00:00 2001
From: Michal Pecio <[email protected]>
Date: Thu, 25 Jan 2024 17:27:37 +0200
Subject: [PATCH] xhci: handle isoc Babble and Buffer Overrun events properly

xHCI 4.9 explicitly forbids assuming that the xHC has released its ownership of a multi-TRB TD when it reports an error on one of the early TRBs. Yet the driver makes such assumption and releases the TD, allowing the remaining TRBs to be freed or overwritten by new TDs.

The xHC should also report completion of the final TRB due to its IOC flag being set by us, regardless of prior errors. This event cannot be recognized if the TD has already been freed earlier, resulting in "Transfer event TRB DMA ptr not part of current TD" error message.

Fix this by reusing the logic for processing isoc Transaction Errors. This also handles hosts which fail to report the final completion.

Fix transfer length reporting on Babble errors. They may be caused by device malfunction, no guarantee that the buffer has been filled.

index 41be7d31a36e..f0d8a607ff21 100644
@@ -2394,9 +2394,13 @@ static int process_isoc_td(struct xhci_hcd *xhci, struct xhci_virt_ep *ep,
 	case COMP_BANDWIDTH_OVERRUN_ERROR:
 		frame->status = -ECOMM;
 		break;
-	case COMP_ISOCH_BUFFER_OVERRUN:
 	case COMP_BABBLE_DETECTED_ERROR:
+		sum_trbs_for_length = true;
+		fallthrough;
+	case COMP_ISOCH_BUFFER_OVERRUN:
 		frame->status = -EOVERFLOW;
+		if (ep_trb != td->last_trb)
+			td->error_mid_td = true;
 		break;
 	case COMP_INCOMPATIBLE_DEVICE_ERROR:
 	case COMP_STALL_ERROR:

Hi,

This patch depends on its parent 5372c65e1311 ("xhci: process isoc TD properly when there was a transaction error mid TD.").

The parent commit appears to be missing from your 5.10 and earlier queues for some reason, hence the breakage.

Regards,
Michal

That parent commit would not apply to those older kernels (and I had no hint that it should go there.) I've backported it to 5.10.y ok, but 5.4 and 4.19 were harder. So if you want both of these in those older kernels, please provide working backports and I'll be glad to queue them up.

thanks,

greg k-h

Nope, my 5.10.y backport failed too, so will need working versions for that tree as well.

thanks,

greg k-h