xhci: Check if slot is already in default state before moving it there

Solves xhci error cases with debug messages:
xhci_hcd 0000:00:14.0: Setup ERROR: setup context command for slot 1.
usb 1-6: hub failed to enable device, error -22

xhci will give a context state error if we try to set a slot in default
state to the same default state with a special address device command.

Turns out this happends in several cases:
- retry reading the device rescriptor in hub_port_init()
- usb_reset_device() is called for a slot in default state
- in resume path, usb_port_resume() calls hub_port_init()

The default state is usually reached from most states with a reset device
command without any context state errors, but using the address device
command with BSA bit set (block set address) only works from the enabled
state and will otherwise cause context error.

solve this by checking if we are already in the default state before issuing
a address device BSA=1 command.

Fixes: 48fc7dbd52c0 ("usb: xhci: change enumeration scheme to 'new scheme'")
Cc: <stable@vger.kernel.org> # v3.14+
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 01fcbb5eb06e7ec3d03bcd81d90941f889c5654a..c50d8d202618521793b37a8bd57d7b343cd757fd 100644 (file)
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -3803,6 +3803,15 @@ static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev,
                return -EINVAL;
        }
 
+       if (setup == SETUP_CONTEXT_ONLY) {
+               slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->out_ctx);
+               if (GET_SLOT_STATE(le32_to_cpu(slot_ctx->dev_state)) ==
+                   SLOT_STATE_DEFAULT) {
+                       xhci_dbg(xhci, "Slot already in default state\n");
+                       return 0;
+               }
+       }
+
        command = xhci_alloc_command(xhci, false, false, GFP_KERNEL);
        if (!command)
                return -ENOMEM;