xhci: fix oops when xhci resumes from hibernate with hw lpm capable devices

[cascardo/linux.git] / drivers / usb / host / xhci.c

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index c020b09..c4a8fca 100644 (file)
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -3971,13 +3971,21 @@ static int __maybe_unused xhci_change_max_exit_latency(struct xhci_hcd *xhci,
        int ret;
 
        spin_lock_irqsave(&xhci->lock, flags);
-       if (max_exit_latency == xhci->devs[udev->slot_id]->current_mel) {
+
+       virt_dev = xhci->devs[udev->slot_id];
+
+       /*
+        * virt_dev might not exists yet if xHC resumed from hibernate (S4) and
+        * xHC was re-initialized. Exit latency will be set later after
+        * hub_port_finish_reset() is done and xhci->devs[] are re-allocated
+        */
+
+       if (!virt_dev || max_exit_latency == virt_dev->current_mel) {
                spin_unlock_irqrestore(&xhci->lock, flags);
                return 0;
        }
 
        /* Attempt to issue an Evaluate Context command to change the MEL. */
-       virt_dev = xhci->devs[udev->slot_id];
        command = xhci->lpm_command;
        ctrl_ctx = xhci_get_input_control_ctx(xhci, command->in_ctx);
        if (!ctrl_ctx) {