[PATCH 5.15 087/107] usb: xhci-mtk: fix bandwidth release issue

Greg Kroah-Hartman
2022-09-06T13:58:24Z

From: Chunfeng Yun <chunfeng.yun@mediatek.com>

commit 6020f480004a80cdad4ae5ee180a231c4f65595b upstream.

This happens when @udev->reset_resume is set to true, when usb resume,
the flow as below:
- hub_resume
- usb_disable_interface
- usb_disable_endpoint
- usb_hcd_disable_endpoint
- xhci_endpoint_disable // it set @ep->hcpriv to NULL

Then when reset usb device, it will drop allocated endpoints,
the flow as below:
- usb_reset_and_verify_device
- usb_hcd_alloc_bandwidth
- xhci_mtk_drop_ep

but @ep->hcpriv is already set to NULL, the bandwidth will be not
released anymore.

Due to the added endponts are stored in hash table, we can drop the check
of @ep->hcpriv.

Fixes: 4ce186665e7c ("usb: xhci-mtk: Do not use xhci's virt_dev in drop_endpoint")
Cc: stable <stable@kernel.org>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20220819080556.32215-2-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/host/xhci-mtk-sch.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/usb/host/xhci-mtk-sch.c
+++ b/drivers/usb/host/xhci-mtk-sch.c
@@ -815,8 +815,8 @@ int xhci_mtk_drop_ep(struct usb_hcd *hcd
if (ret)
return ret;

- if (ep->hcpriv)
- drop_ep_quirk(hcd, udev, ep);
+ /* needn't check @ep->hcpriv, xhci_endpoint_disable set it NULL */
+ drop_ep_quirk(hcd, udev, ep);

return 0;
}