Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754348AbaDOTFX (ORCPT ); Tue, 15 Apr 2014 15:05:23 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:42680 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752699AbaDOTFU (ORCPT ); Tue, 15 Apr 2014 15:05:20 -0400 Date: Tue, 15 Apr 2014 15:05:19 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Stefani Seibold cc: linux-usb , , Greg KH , , Subject: Re: Missing USB XHCI and EHCI reset for kexec In-Reply-To: <1397586749.20840.6.camel@vger.seibold.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 15 Apr 2014, Stefani Seibold wrote: > > 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 > > > > I tried this, when i increase the value to 1000, the reset and > enumeration process will be faster after a kexec: 28 Seconds vs. 162 > Seconds. Even 28 seconds is much longer than it should be. And a 1000-ms long reset signal is a lot longer than any device should need. Anyway, since you saw the same problem after unbind and rebind, you don't have to perform a kexec for testing. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/