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From:   Bernhard Gebetsberger <bernhard.gebetsberger@gmx.at>
Cc:     Bernhard Gebetsberger <bernhard.gebetsberger@gmx.at>,
        Mathias Nyman <mathias.nyman@intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-usb@vger.kernel.org (open list:USB XHCI DRIVER),
        linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] xhci: Don't use soft retry if slot id > 0
Date:   Sun, 13 Oct 2019 02:33:13 +0200
Message-Id: <20191013003313.3497-1-bernhard.gebetsberger@gmx.at>
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Sender: linux-kernel-owner@vger.kernel.org
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According to the xhci specification(chapter 4.6.8.1) soft retry
shouldn't be used if the slot id is higher than 0. Currently some usb
devices break on some systems because soft retry is being used when
there is a transaction error, without checking the slot id.

Fixes: f8f80be501aa ("xhci: Use soft retry to recover faster from
transaction errors")

Signed-off-by: Bernhard Gebetsberger <bernhard.gebetsberger@gmx.at>
=2D--
 drivers/usb/host/xhci-ring.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 85ceb43e3405..5fa06189068d 100644
=2D-- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2270,7 +2270,7 @@ static int process_bulk_intr_td(struct xhci_hcd *xhc=
i, struct xhci_td *td,
 		break;
 	case COMP_USB_TRANSACTION_ERROR:
 		if ((ep_ring->err_count++ > MAX_SOFT_RETRY) ||
-		    le32_to_cpu(slot_ctx->tt_info) & TT_SLOT)
+		    le32_to_cpu(slot_ctx->tt_info) & TT_SLOT || slot_id > 0)
 			break;
 		*status =3D 0;
 		xhci_cleanup_halted_endpoint(xhci, slot_id, ep_index,
=2D-
2.23.0