2 files changed, 14 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 497ed7723e44..ec4338eec826 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1815,6 +1815,8 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
         xhci->event_ring = NULL;
         xhci_dbg(xhci, "Freed event ring\n");
 
+        if (xhci->lpm_command)
+                xhci_free_command(xhci, xhci->lpm_command);
         xhci->cmd_ring_reserved_trbs = 0;
         if (xhci->cmd_ring)
                 xhci_ring_free(xhci, xhci->cmd_ring);
@@ -2377,6 +2379,16 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
         xhci_write_64(xhci, val_64, &xhci->op_regs->cmd_ring);
         xhci_dbg_cmd_ptrs(xhci);
 
+        xhci->lpm_command = xhci_alloc_command(xhci, true, true, flags);
+        if (!xhci->lpm_command)
+                goto fail;
+
+        /* Reserve one command ring TRB for disabling LPM.
+         * Since the USB core grabs the shared usb_bus bandwidth mutex before
+         * disabling LPM, we only need to reserve one TRB for all devices.
+         */
+        xhci->cmd_ring_reserved_trbs++;
+
         val = xhci_readl(xhci, &xhci->cap_regs->db_off);
         val &= DBOFF_MASK;
         xhci_dbg(xhci, "// Doorbell array is located at offset 0x%x"
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 59248449b254..f5cb7417f231 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1426,6 +1426,8 @@ struct xhci_hcd {
         /* slot enabling and address device helpers */
         struct completion       addr_dev;
         int slot_id;
+        /* For USB 3.0 LPM enable/disable. */
+        struct xhci_command             *lpm_command;
         /* Internal mirror of the HW's dcbaa */
         struct xhci_virt_device *devs[MAX_HC_SLOTS];
         /* For keeping track of bandwidth domains per roothub. */