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authorMathias Nyman <mathias.nyman@linux.intel.com>2020-04-21 17:08:22 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-04-29 16:33:23 +0200
commitfceab238c534eca02253c01f3bd5db391acd47b0 (patch)
treee4175f8c138cd973b2c63477784ecbb95e7672d6
parent54470b0bd16aabc05c1d5fe2037e7fadf7869c16 (diff)
xhci: Don't clear hub TT buffer on ep0 protocol stall
commit 8f97250c21f0cf36434bf5b7ddf4377406534cd1 upstream. The default control endpoint ep0 can return a STALL indicating the device does not support the control transfer requests. This is called a protocol stall and does not halt the endpoint. xHC behaves a bit different. Its internal endpoint state will always be halted on any stall, even if the device side of the endpiont is not halted. So we do need to issue the reset endpoint command to clear the xHC host intenal endpoint halt state, but should not request the HS hub to clear the TT buffer unless device side of endpoint is halted. Clearing the hub TT buffer at protocol stall caused ep0 to become unresponsive for some FS/LS devices behind HS hubs, and class drivers failed to set the interface due to timeout: usb 1-2.1: 1:1: usb_set_interface failed (-110) Fixes: ef513be0a905 ("usb: xhci: Add Clear_TT_Buffer") Cc: <stable@vger.kernel.org> # v5.3 Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200421140822.28233-4-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/host/xhci-ring.c16
1 files changed, 11 insertions, 5 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 9159208e2580..a54f8f3234f9 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1868,7 +1868,6 @@ static void xhci_cleanup_halted_endpoint(struct xhci_hcd *xhci,
ep->ep_state |= EP_HARD_CLEAR_TOGGLE;
xhci_cleanup_stalled_ring(xhci, slot_id, ep_index, stream_id,
td);
- xhci_clear_hub_tt_buffer(xhci, td, ep);
}
xhci_ring_cmd_db(xhci);
}
@@ -1989,11 +1988,18 @@ static int finish_td(struct xhci_hcd *xhci, struct xhci_td *td,
if (trb_comp_code == COMP_STALL_ERROR ||
xhci_requires_manual_halt_cleanup(xhci, ep_ctx,
trb_comp_code)) {
- /* Issue a reset endpoint command to clear the host side
- * halt, followed by a set dequeue command to move the
- * dequeue pointer past the TD.
- * The class driver clears the device side halt later.
+ /*
+ * xhci internal endpoint state will go to a "halt" state for
+ * any stall, including default control pipe protocol stall.
+ * To clear the host side halt we need to issue a reset endpoint
+ * command, followed by a set dequeue command to move past the
+ * TD.
+ * Class drivers clear the device side halt from a functional
+ * stall later. Hub TT buffer should only be cleared for FS/LS
+ * devices behind HS hubs for functional stalls.
*/
+ if ((ep_index != 0) || (trb_comp_code != COMP_STALL_ERROR))
+ xhci_clear_hub_tt_buffer(xhci, td, ep);
xhci_cleanup_halted_endpoint(xhci, slot_id, ep_index,
ep_ring->stream_id, td, EP_HARD_RESET);
} else {