archive mirror
 help / color / mirror / Atom feed
From: Adrian Zaharia <>
To: <>
Cc: <>, <>,
	<>, <>
Subject: [PATCH 5.10 1/1] xhci: Set HCD flag to defer primary roothub registration
Date: Wed, 25 Jan 2023 15:33:59 +0200	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

From: Kishon Vijay Abraham I <>

[ Upstream commit b7a4f9b5d0e4b6dd937678c546c0b322dd1a4054 ]

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

[minor rebase change, and commit message update -Mathias]

CC: # 5.4+
Suggested-by: Mathias Nyman <>
Tested-by: Chris Chiu <>
Signed-off-by: Kishon Vijay Abraham I <>
Signed-off-by: Adrian Zaharia <>
 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 2967372a9988..473b0b64dd57 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);

  reply	other threads:[~2023-01-25 13:35 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-25 13:33 [PATCH 5.10 0/1] backport of 'xhci: Set HCD flag to defer primary roothub registration' Adrian Zaharia
2023-01-25 13:33 ` Adrian Zaharia [this message]
2023-01-27  7:25   ` [PATCH 5.10 1/1] xhci: Set HCD flag to defer primary roothub registration Greg KH

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).