* [PATCH] xhci: Reset controller on xhci shutdown
@ 2026-10-01 22:25 wenxiong
2026-10-01 22:40 ` Mathias Nyman
2026-10-02 8:29 ` Michal Pecio
0 siblings, 2 replies; 3+ messages in thread
From: wenxiong @ 2026-10-01 22:25 UTC (permalink / raw)
To: mathias.nyman, gregkh
Cc: linux-usb, linux-kernel, stable, wenxiong, Wen Xiong, Brian King,
Samuel Mendoza-Jonas, Joel Stanley
From: Wen Xiong <wenxiong@linux.ibm.com>
Fixes kexec boot. Without a hard reset, some USB chips will fail to
initialize in a kexec booted kernel.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Wen Xiong <wenxiong@linux.ibm.com>
---
drivers/usb/host/xhci.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index a9e47e178c28..364bd61a4bd7 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -781,6 +781,9 @@ void xhci_shutdown(struct usb_hcd *hcd)
xhci_dbg_trace(xhci, trace_xhci_dbg_init,
"xhci_shutdown completed - status = %x",
readl(&xhci->op_regs->status));
+
+ /* TI XHCI controllers do not come back after kexec without this hack */
+ pci_reset_function_locked(to_pci_dev(hcd->self.sysdev));
}
EXPORT_SYMBOL_GPL(xhci_shutdown);
--
2.52.0
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] xhci: Reset controller on xhci shutdown
2026-10-01 22:25 [PATCH] xhci: Reset controller on xhci shutdown wenxiong
@ 2026-10-01 22:40 ` Mathias Nyman
2026-10-02 8:29 ` Michal Pecio
1 sibling, 0 replies; 3+ messages in thread
From: Mathias Nyman @ 2026-10-01 22:40 UTC (permalink / raw)
To: wenxiong, mathias.nyman, gregkh
Cc: linux-usb, linux-kernel, stable, wenxiong, Brian King,
Samuel Mendoza-Jonas, Joel Stanley
Hi
On 10/2/26 01:25, wenxiong@linux.ibm.com wrote:
> From: Wen Xiong <wenxiong@linux.ibm.com>
>
> Fixes kexec boot. Without a hard reset, some USB chips will fail to
> initialize in a kexec booted kernel.
>
> Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
> Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
> Signed-off-by: Joel Stanley <joel@jms.id.au>
> Signed-off-by: Wen Xiong <wenxiong@linux.ibm.com>
> ---
> drivers/usb/host/xhci.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index a9e47e178c28..364bd61a4bd7 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -781,6 +781,9 @@ void xhci_shutdown(struct usb_hcd *hcd)
> xhci_dbg_trace(xhci, trace_xhci_dbg_init,
> "xhci_shutdown completed - status = %x",
> readl(&xhci->op_regs->status));
> +
> + /* TI XHCI controllers do not come back after kexec without this hack */
> + pci_reset_function_locked(to_pci_dev(hcd->self.sysdev));
> }
> EXPORT_SYMBOL_GPL(xhci_shutdown);
>
Should be added to xhci-pci.c: xhci_pci_shutdown() instead.
Probably also limited to that specific TI xHC controller
Thanks
Mathias
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] xhci: Reset controller on xhci shutdown
2026-10-01 22:25 [PATCH] xhci: Reset controller on xhci shutdown wenxiong
2026-10-01 22:40 ` Mathias Nyman
@ 2026-10-02 8:29 ` Michal Pecio
1 sibling, 0 replies; 3+ messages in thread
From: Michal Pecio @ 2026-10-02 8:29 UTC (permalink / raw)
To: wenxiong
Cc: mathias.nyman, gregkh, linux-usb, linux-kernel, stable, wenxiong,
Brian King, Samuel Mendoza-Jonas, Joel Stanley
On Thu, 1 Oct 2026 18:25:27 -0400, wenxiong@linux.ibm.com wrote:
> From: Wen Xiong <wenxiong@linux.ibm.com>
>
> Fixes kexec boot. Without a hard reset, some USB chips will fail to
> initialize in a kexec booted kernel.
What exactly happens after kexec?
Why a PCI reset in particular?
Are we sure it's not a bug elsewhere?
Regards,
Michal
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-10-02 8:29 UTC | newest]
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2026-10-01 22:25 [PATCH] xhci: Reset controller on xhci shutdown wenxiong
2026-10-01 22:40 ` Mathias Nyman
2026-10-02 8:29 ` Michal Pecio
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