Re: Missing USB XHCI and EHCI reset for kexec

From: Alan Stern
Date: Mon Apr 14 2014 - 13:58:33 EST


On Mon, 14 Apr 2014, Stefani Seibold wrote:

> > > An other PowerPC device which is nearly eactly the same HW but without
> > > this USB HUB works perfectly.
> >
> > Maybe you should replace that hub with a different brand.
> >
>
> Thats not possible, because the Hub is soldered on the board. And it is
> also not a HW issue, since the Hub works perfectly which all previous
> kernels including 3.4.

One other thing you can try is to increase the reset timeout in
drivers/usb/host/ehci-hub.c. This is under the USB_PORT_FEAT_RESET
case in ehci_hub_control(), around line 1225:

/*
* caller must wait, then call GetPortStatus
* usb 2.0 spec says 50 ms resets on root
*/
ehci->reset_done [wIndex] = jiffies
+ msecs_to_jiffies (50);

Increasing the 50 to 100 or more might help.

Alan Stern

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