From: Wen Xiong <wenxiong@linux.ibm.com>
To: Michal Pecio <michal.pecio@gmail.com>
Cc: mathias.nyman@intel.com, gregkh@linuxfoundation.org,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
stable@vger.kernel.org, wenxiong@us.ibm.com,
Brian King <brking@linux.vnet.ibm.com>,
Samuel Mendoza-Jonas <sam@mendozajonas.com>,
Joel Stanley <joel@jms.id.au>
Subject: Re: [PATCH] xhci: Reset controller on xhci shutdown
Date: Wed, 14 Oct 2026 15:32:22 -0500 [thread overview]
Message-ID: <64515dfd9a6cd8c3f5665e72a6bf6b81@linux.ibm.com> (raw)
In-Reply-To: <20261006125546.10471489.michal.pecio@gmail.com>
On 2026-10-06 05:55, Michal Pecio wrote:
> Are you able to capture the original kernel's dmesg (through serial,
> netconsole, etc) and see if the same "Host halt failed" is there?
>
Below is xhci messages after executing a kexec kernel. This is dmesg for
kexec kernel.
[root@ltc-boston11 ~]# dmesg|grep xhci
[ 1.085853] xhci_hcd 0005:01:00.0: xHCI Host Controller
[ 1.085992] xhci_hcd 0005:01:00.0: new USB bus registered, assigned
bus number 1
[ 1.144472] xhci_hcd 0005:01:00.0: Host halt failed, -110
[ 1.144518] xhci_hcd 0005:01:00.0: can't setup: -110
[ 1.144571] xhci_hcd 0005:01:00.0: USB bus 1 deregistered
[ 1.144778] xhci_hcd 0005:01:00.0: init 0005:01:00.0 fail, -110
[ 1.144842] xhci_hcd 0005:01:00.0: probe with driver xhci_hcd failed
with error -110
This is the reason why we can't see usb devices after a kexec kernel.
With the patch,
#dmesg|grep xhci
[ 0.859562] xhci_hcd 0005:01:00.0: xHCI Host Controller
[ 0.859670] xhci_hcd 0005:01:00.0: new USB bus registered, assigned
bus number 1
[ 0.859797] xhci_hcd 0005:01:00.0: iommu: 64-bit OK but direct DMA is
limited by 0
[ 0.859858] xhci_hcd 0005:01:00.0: iommu: 64-bit OK but direct DMA is
limited by 0
[ 0.859982] xhci_hcd 0005:01:00.0: hcc params 0x0270f06d hci version
0x96 quirks 0x0000000004000000
[ 0.860614] xhci_hcd 0005:01:00.0: xHCI Host Controller
[ 0.860719] xhci_hcd 0005:01:00.0: new USB bus registered, assigned
bus number 2
[ 0.860770] xhci_hcd 0005:01:00.0: Host supports USB 3.0 SuperSpeed
[ 0.861091] usb usb1: Manufacturer: Linux 7.3.0-rc6-usb-gbatra+
xhci-hcd
[ 0.862130] usb usb2: Manufacturer: Linux 7.3.0-rc6-usb-gbatra+
xhci-hcd
[ 1.127210] usb 1-3: new high-speed USB device number 2 using
xhci_hcd
[ 1.407320] usb 2-2: new SuperSpeed USB device number 2 using
xhci_hcd
[ 1.556759] usb 1-4: new high-speed USB device number 3 using
xhci_hcd
[ 1.806902] usb 1-3.1: new low-speed USB device number 4 using
xhci_hcd
#[root@ltc-boston11 ~]# lsusb
Bus 002 Device 002: ID 18a5:0252 Verbatim, Ltd
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 0451:80ff Texas Instruments, Inc.
Bus 001 Device 004: ID 0557:2419 ATEN International Co., Ltd Virtual
mouse/keyboard device
Bus 001 Device 002: ID 0557:7000 ATEN International Co., Ltd Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
> And if you enable dynamic debug before kexec,
>
> echo 'module xhci_hcd +p' >/proc/dynamic_debug/control
>
> what's printed by the debug message at the end of xhci_shutdown()?
>
> Do you also get errors from quirk_usb_handoff_xhci() by any chance?
>
After executing a kexec kernel, is the control setting lost?
I didn't see much useful information in control after a kexec kernel.
Probably we can resubmit the patch with mathias's suggestion.
Thanks,
Wendy
T
prev parent reply other threads:[~2026-10-14 20:32 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-01 22:25 [PATCH] xhci: Reset controller on xhci shutdown wenxiong
2026-10-01 22:40 ` Mathias Nyman
2026-10-02 14:08 ` Wen Xiong
2026-10-02 8:29 ` Michal Pecio
2026-10-02 14:05 ` Wen Xiong
2026-10-02 14:18 ` Michal Pecio
2026-10-05 13:01 ` Wen Xiong
2026-10-06 10:55 ` Michal Pecio
2026-10-14 20:32 ` Wen Xiong [this message]
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