The xHCI hub port code gets passed a zero-based port number by the USB
core. It then adds one to in order to find a device slot by port number
and device speed by calling xhci_find_slot_id_by_port. That function
clearly states it requires a one-based port number. The xHCI port
status change event handler was using a zero-based port number that it
got from find_faked_portnum_from_hw_portnum, not a one-based port
number. This lead to the doorbells never being rung for a device after
a resume, or worse, a different device with the same speed having its
doorbell rung (which could lead to bad power management in the xHCI host
controller).
Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
---
drivers/usb/host/xhci-ring.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index b90e138..5a818cb 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1204,6 +1204,7 @@ static void handle_vendor_event(struct xhci_hcd *xhci,
*
* Returns a zero-based port number, which is suitable for indexing into each of
* the split roothubs' port arrays and bus state arrays.
+ * Add one to it in order to call xhci_find_slot_id_by_port.
*/
static unsigned int find_faked_portnum_from_hw_portnum(struct usb_hcd *hcd,
struct xhci_hcd *xhci, u32 port_id)
@@ -1324,7 +1325,7 @@ static void handle_port_status(struct xhci_hcd *xhci,
xhci_set_link_state(xhci, port_array, faked_port_index,
XDEV_U0);
slot_id = xhci_find_slot_id_by_port(hcd, xhci,
- faked_port_index);
+ faked_port_index + 1);
if (!slot_id) {
xhci_dbg(xhci, "slot_id is zero\n");
goto cleanup;
--
1.7.5.4
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