Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751382AbaKDQ6j (ORCPT ); Tue, 4 Nov 2014 11:58:39 -0500 Received: from iolanthe.rowland.org ([192.131.102.54]:51317 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751035AbaKDQ6i (ORCPT ); Tue, 4 Nov 2014 11:58:38 -0500 Date: Tue, 4 Nov 2014 11:58:37 -0500 (EST) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Lu Baolu cc: Mathias Nyman , Greg Kroah-Hartman , , Subject: Re: [PATCH v2 2/3] usb: xhci: This reworks ff8cbf250b448aac35589f6075082c3fcad8a8fe In-Reply-To: <1415090066-57007-3-git-send-email-baolu.lu@linux.intel.com> 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, 4 Nov 2014, Lu Baolu wrote: > xhci: clear root port wake on bits if controller isn't wake-up capable > > When system is being suspended, if host device is not wakeup capable, > xhci_suspend() needs to clear all root port wake on bits. Otherwise, > some platforms may generate spurious wakeup, even if PCI PME# is dis- > abled. > > Signed-off-by: Lu Baolu > --- > drivers/usb/host/xhci.c | 42 ++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 42 insertions(+) > > diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c > index 2a5d45b..cd57aae 100644 > --- a/drivers/usb/host/xhci.c > +++ b/drivers/usb/host/xhci.c > @@ -35,6 +35,8 @@ > #define DRIVER_AUTHOR "Sarah Sharp" > #define DRIVER_DESC "'eXtensible' Host Controller (xHC) Driver" > > +#define PORT_WAKE_BITS (PORT_WKOC_E | PORT_WKDISC_E | PORT_WKCONN_E) > + > /* Some 0.95 hardware can't handle the chain bit on a Link TRB being cleared */ > static int link_quirk; > module_param(link_quirk, int, S_IRUGO | S_IWUSR); > @@ -851,6 +853,42 @@ static void xhci_clear_command_ring(struct xhci_hcd *xhci) > xhci_set_cmd_ring_deq(xhci); > } > > +static void xhci_disable_port_wake_on_bits(struct xhci_hcd *xhci) > +{ > + int port_index; > + __le32 __iomem **port_array; > + unsigned long flags; > + u32 t1, t2; > + > + spin_lock_irqsave(&xhci->lock, flags); > + > + /* disble usb3 ports Wake bits*/ > + port_index = xhci->num_usb3_ports; > + port_array = xhci->usb3_ports; > + while (port_index--) { > + t1 = readl(port_array[port_index]); > + t2 = xhci_port_state_to_neutral(t1); > + t2 &= ~PORT_WAKE_BITS; > + t1 = xhci_port_state_to_neutral(t1); > + if (t1 != t2) > + writel(t2, port_array[port_index]); > + } > + > + /* disble usb2 ports Wake bits*/ > + port_index = xhci->num_usb2_ports; > + port_array = xhci->usb2_ports; > + while (port_index--) { > + t1 = readl(port_array[port_index]); > + t2 = xhci_port_state_to_neutral(t1); > + t2 &= ~PORT_WAKE_BITS; > + t1 = xhci_port_state_to_neutral(t1); > + if (t1 != t2) > + writel(t2, port_array[port_index]); > + } > + > + spin_unlock_irqrestore(&xhci->lock, flags); > +} > + > /* > * Stop HC (not bus-specific) > * > @@ -868,6 +906,10 @@ int xhci_suspend(struct xhci_hcd *xhci) > xhci->shared_hcd->state != HC_STATE_SUSPENDED) > return -EINVAL; > > + /* Clear root port wake on bits if not wakeup capable. */ > + if (!device_may_wakeup(hcd->self.controller)) > + xhci_disable_port_wake_on_bits(xhci); > + > /* Don't poll the roothubs on bus suspend. */ > xhci_dbg(xhci, "%s: stopping port polling.\n", __func__); > clear_bit(HCD_FLAG_POLL_RH, &hcd->flags); This is better but still wrong. Remember, this same code gets called for system suspend _and_ for runtime suspend. During runtime suspend, wakeup is always supposed to be turned on, even if device_may_wakeup() is false. That's because device_may_wakeup() refers only to system suspend. What you need to test is the do_wakeup flag, which should be passed into xhci_suspend() by xhci_pci_suspend() and xhci_plat_suspend(). Another problem is in the patch description and the comments. If device_may_wakeup() returns false, it doesn't mean the controller isn't wakeup-capable -- it means the controller isn't _allowed_ to wake up the system. Those are two different things. Finally, the code in xhci_disable_port_wake_on_bits() looks a little peculiar -- I'm not sure about all those calls to xhci_port_state_to_neutral(). But I'm not an expert on that; Mathias will have to advise on it. 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/