From akpm@osdl.org Fri Jun 30 16:39:44 2006 Message-Id: <200606300934.k5U9YgNT001781@shell0.pdx.osdl.net> From: David Brownell Subject: USB: ehci: fix bogus alteration of a local variable To: greg@kroah.com Cc: akpm@osdl.org, david-b@pacbell.net, dbrownell@users.sourceforge.net, saxofon@musiker.nu Date: Fri, 30 Jun 2006 02:34:42 -0700 From: David Brownell In a rare and all-but-unused path, the EHCI driver could reuse a variable in a way that'd make trouble. Specifically, if the first root hub port gets an overcurrent event (rare) during a remote wakeup scenario (all but unused in today's Linux, except for folk working with suspend-to-RAM and similar sleep states), that would look like a fatal error which would shut down the controller. Fix by not reusing that variable. Spotted by Per Hallsmark Fixes http://bugzilla.kernel.org/show_bug.cgi?id=6661 Signed-off-by: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-hcd.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- gregkh-2.6.orig/drivers/usb/host/ehci-hcd.c +++ gregkh-2.6/drivers/usb/host/ehci-hcd.c @@ -625,10 +625,11 @@ static irqreturn_t ehci_irq (struct usb_ writel (status | CMD_RUN, &ehci->regs->command); while (i--) { - status = readl (&ehci->regs->port_status [i]); - if (status & PORT_OWNER) + int pstatus = readl (&ehci->regs->port_status [i]); + + if (pstatus & PORT_OWNER) continue; - if (!(status & PORT_RESUME) + if (!(pstatus & PORT_RESUME) || ehci->reset_done [i] != 0) continue;