linux-kernel - Re: your mail

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Pine.LNX.4.44L0.0805201117430.2114-100000@iolanthe.rowland.org>
Date:	Tue, 20 May 2008 11:20:10 -0400 (EDT)
From:	Alan Stern <stern@...land.harvard.edu>
To:	Lukas Hejtmanek <xhejtman@....muni.cz>
cc:	Oliver Neukum <oliver@...kum.org>,
	"Rafael J. Wysocki" <rjw@...k.pl>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	<greg@...ah.com>, <linux-usb@...r.kernel.org>
Subject: Re: your mail

On Tue, 20 May 2008, Lukas Hejtmanek wrote:

> <stern@...land.harvard.edu>, Greg KH <greg@...ah.com>
> Bcc: 
> Subject: Re: [Bug #10630] USB devices plugged into dock are not discoverred
> 	until reload of ehci-hcd
> Reply-To: 
> In-Reply-To: <200805201327.34678.oliver@...kum.org>
> X-echelon: NSA, CIA, CI5, MI5, FBI, KGB, BIS, Plutonium, Bin Laden, bomb
> 
> On Tue, May 20, 2008 at 01:27:34PM +0200, Oliver Neukum wrote:
> > > done.
> > > http://bugzilla.kernel.org/show_bug.cgi?id=10630
> > 
> > Aha. Thanks.
> > Please recompile without CONFIG_USB_SUSPEND
> 
> Hm, without USB_SUSPEND it works. So what next, considered fixed or any
> further investigation is needed?

No further investigation is needed.  I tried doing essentially the same 
thing on my system and the same problem occurred.

It is caused by the way ehci-hcd "auto-clears" the port
change-suspend feature.  This patch should fix the problem.  Please 
try it out and let us know if it works.

Alan Stern



Index: usb-2.6/drivers/usb/host/ehci.h
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci.h
+++ usb-2.6/drivers/usb/host/ehci.h
@@ -97,6 +97,8 @@ struct ehci_hcd {			/* one per controlle
 			dedicated to the companion controller */
 	unsigned long		owned_ports;		/* which ports are
 			owned by the companion during a bus suspend */
+	unsigned long		port_c_suspend;		/* which ports have
+			the change-suspend feature turned on */
 
 	/* per-HC memory pools (could be per-bus, but ...) */
 	struct dma_pool		*qh_pool;	/* qh per active urb */
Index: usb-2.6/drivers/usb/host/ehci-hub.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-hub.c
+++ usb-2.6/drivers/usb/host/ehci-hub.c
@@ -609,7 +609,7 @@ static int ehci_hub_control (
 			}
 			break;
 		case USB_PORT_FEAT_C_SUSPEND:
-			/* we auto-clear this feature */
+			clear_bit(wIndex, &ehci->port_c_suspend);
 			break;
 		case USB_PORT_FEAT_POWER:
 			if (HCS_PPC (ehci->hcs_params))
@@ -688,7 +688,7 @@ static int ehci_hub_control (
 			/* resume completed? */
 			else if (time_after_eq(jiffies,
 					ehci->reset_done[wIndex])) {
-				status |= 1 << USB_PORT_FEAT_C_SUSPEND;
+				set_bit(wIndex, &ehci->port_c_suspend);
 				ehci->reset_done[wIndex] = 0;
 
 				/* stop resume signaling */
@@ -765,6 +765,8 @@ static int ehci_hub_control (
 			status |= 1 << USB_PORT_FEAT_RESET;
 		if (temp & PORT_POWER)
 			status |= 1 << USB_PORT_FEAT_POWER;
+		if (test_bit(wIndex, &ehci->port_c_suspend))
+			status |= 1 << USB_PORT_FEAT_C_SUSPEND;
 
 #ifndef	VERBOSE_DEBUG
 	if (status & ~0xffff)	/* only if wPortChange is interesting */

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/