From cc7c2818c71ebace207df40cc586c8c74e3d1a59 Mon Sep 17 00:00:00 2001 From: Mathias Nyman Date: Fri, 10 Dec 2021 16:17:35 +0200 Subject: [PATCH] xhci: avoid race between disable slot command and host runtime suspend commit 7faac1953ed1f658f719cdf7bb7303fa5eef822c upstream. Make xhci_disable_slot() synchronous, thus ensuring it, and xhci_free_dev() calling it return after xHC controller completes the disable slot command. Otherwise the roothub and xHC host may runtime suspend, and clear the command ring while the disable slot command is being processed. This causes a command completion mismatch as the completion event can't be mapped to the correct command. Command ring gets out of sync and commands time out. Driver finally assumes host is unresponsive and bails out. usb 2-4: USB disconnect, device number 10 xhci_hcd 0000:00:0d.0: ERROR mismatched command completion event ... xhci_hcd 0000:00:0d.0: xHCI host controller not responding, assume dead xhci_hcd 0000:00:0d.0: HC died; cleaning up Cc: Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/20211210141735.1384209-3-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-hub.c | 1 + drivers/usb/host/xhci-ring.c | 1 - drivers/usb/host/xhci.c | 22 +++++++++++++++------- 3 files changed, 16 insertions(+), 8 deletions(-) diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c index 224d0bdda82ff..cf5af8592f3d8 100644 --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -625,6 +625,7 @@ static int xhci_enter_test_mode(struct xhci_hcd *xhci, continue; retval = xhci_disable_slot(xhci, i); + xhci_free_virt_device(xhci, i); if (retval) xhci_err(xhci, "Failed to disable slot %d, %d. Enter test mode anyway\n", i, retval); diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 15e3bf8c9e830..f5bd91752f2d2 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1236,7 +1236,6 @@ static void xhci_handle_cmd_disable_slot(struct xhci_hcd *xhci, int slot_id) if (xhci->quirks & XHCI_EP_LIMIT_QUIRK) /* Delete default control endpoint resources */ xhci_free_device_endpoint_resources(xhci, virt_dev, true); - xhci_free_virt_device(xhci, slot_id); } static void xhci_handle_cmd_config_ep(struct xhci_hcd *xhci, int slot_id, diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index b1643fd9830c6..0c2b726b7797c 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -3836,9 +3836,8 @@ static void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev) } xhci_debugfs_remove_slot(xhci, udev->slot_id); virt_dev->udev = NULL; - ret = xhci_disable_slot(xhci, udev->slot_id); - if (ret) - xhci_free_virt_device(xhci, udev->slot_id); + xhci_disable_slot(xhci, udev->slot_id); + xhci_free_virt_device(xhci, udev->slot_id); } int xhci_disable_slot(struct xhci_hcd *xhci, u32 slot_id) @@ -3848,7 +3847,7 @@ int xhci_disable_slot(struct xhci_hcd *xhci, u32 slot_id) u32 state; int ret = 0; - command = xhci_alloc_command(xhci, false, GFP_KERNEL); + command = xhci_alloc_command(xhci, true, GFP_KERNEL); if (!command) return -ENOMEM; @@ -3871,6 +3870,15 @@ int xhci_disable_slot(struct xhci_hcd *xhci, u32 slot_id) } xhci_ring_cmd_db(xhci); spin_unlock_irqrestore(&xhci->lock, flags); + + wait_for_completion(command->completion); + + if (command->status != COMP_SUCCESS) + xhci_warn(xhci, "Unsuccessful disable slot %u command, status %d\n", + slot_id, command->status); + + xhci_free_command(xhci, command); + return ret; } @@ -3979,9 +3987,8 @@ int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev) return 1; disable_slot: - ret = xhci_disable_slot(xhci, udev->slot_id); - if (ret) - xhci_free_virt_device(xhci, udev->slot_id); + xhci_disable_slot(xhci, udev->slot_id); + xhci_free_virt_device(xhci, udev->slot_id); return 0; } @@ -4110,6 +4117,7 @@ static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev, mutex_unlock(&xhci->mutex); ret = xhci_disable_slot(xhci, udev->slot_id); + xhci_free_virt_device(xhci, udev->slot_id); if (!ret) xhci_alloc_dev(hcd, udev); kfree(command->completion); -- 2.51.0