From 2a5c17add89692a1556a9a86c32e06c2d4b97f25 Mon Sep 17 00:00:00 2001 From: Kishon Vijay Abraham I Date: Thu, 9 Sep 2021 12:11:59 +0530 Subject: [PATCH 2/2] xhci: Set HCD flag to defer primary roothub registration Set "HCD_FLAG_DEFER_RH_REGISTER" to hcd->flags in xhci_run() to defer registering primary roothub in usb_add_hcd() if xhci has two roothubs. This will make sure both primary roothub and secondary roothub will be registered along with the second HCD. This is required for cold plugged USB devices to be detected in certain PCIe USB cards (like Inateck USB card connected to AM64 EVM or J7200 EVM). This patch has been added and reverted earier as it triggered a race in usb device enumeration. That race is now fixed in 5.16-rc3, and in stable back to 5.4 commit 6cca13de26ee ("usb: hub: Fix locking issues with address0_mutex") commit 6ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race") [minor rebase change, and commit message update -Mathias] CC: stable@vger.kernel.org # 5.4+ Suggested-by: Mathias Nyman Tested-by: Chris Chiu Signed-off-by: Kishon Vijay Abraham I --- drivers/usb/host/xhci.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 642610c78f58..7665845a80df 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -696,6 +696,8 @@ int xhci_run(struct usb_hcd *hcd) xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Finished xhci_run for USB2 roothub"); + set_bit(HCD_FLAG_DEFER_RH_REGISTER, &hcd->flags); + xhci_create_dbc_dev(xhci); xhci_debugfs_init(xhci); -- 2.25.1