[PATCH v2 1/1] xhci: clear root port wake on bits if controller isn't wake-up capable

[PATCH v2 1/1] xhci: clear root port wake on bits if controller isn't wake-up capable

[Lu Baolu]

When xHCI PCI host is suspended, if do_wakeup is false in xhci_pci_suspend,
xhci_bus_suspend needs to clear all root port wake on bits. Otherwise some Intel
platforms may get a spurious wakeup, even if PCI PME# is disabled.

This patch should be back-ported to kernels as old as 2.6.37, that
contains the commit 9777e3ce907d4cb5a513902a87ecd03b52499569
"USB: xHCI: bus power management implementation". 

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/usb/host/xhci-hub.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 6231ce6..fb771bd 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -22,6 +22,7 @@
 
 
 #include <linux/slab.h>
+#include <linux/device.h>
 #include <asm/unaligned.h>
 
 #include "xhci.h"
@@ -1139,7 +1140,9 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
 		 * including the USB 3.0 roothub, but only if CONFIG_PM_RUNTIME
 		 * is enabled, so also enable remote wake here.
 		 */
-		if (hcd->self.root_hub->do_remote_wakeup) {
+		if (hcd->self.root_hub->do_remote_wakeup
+				&& device_may_wakeup(hcd->self.controller)) {
+
 			if (t1 & PORT_CONNECT) {
 				t2 |= PORT_WKOC_E | PORT_WKDISC_E;
 				t2 &= ~PORT_WKCONN_E;
-- 
1.9.1

Re: [PATCH v2 1/1] xhci: clear root port wake on bits if controller isn't wake-up capable

[Mathias Nyman]

On 06/13/2014 03:06 AM, Lu Baolu wrote:
> When xHCI PCI host is suspended, if do_wakeup is false in xhci_pci_suspend,
> xhci_bus_suspend needs to clear all root port wake on bits. Otherwise some Intel
> platforms may get a spurious wakeup, even if PCI PME# is disabled.
> 
> This patch should be back-ported to kernels as old as 2.6.37, that
> contains the commit 9777e3ce907d4cb5a513902a87ecd03b52499569
> "USB: xHCI: bus power management implementation". 
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>  drivers/usb/host/xhci-hub.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
> index 6231ce6..fb771bd 100644
> --- a/drivers/usb/host/xhci-hub.c
> +++ b/drivers/usb/host/xhci-hub.c
> @@ -22,6 +22,7 @@
>  
>  
>  #include <linux/slab.h>
> +#include <linux/device.h>
>  #include <asm/unaligned.h>
>  
>  #include "xhci.h"
> @@ -1139,7 +1140,9 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
>  		 * including the USB 3.0 roothub, but only if CONFIG_PM_RUNTIME
>  		 * is enabled, so also enable remote wake here.
>  		 */
> -		if (hcd->self.root_hub->do_remote_wakeup) {
> +		if (hcd->self.root_hub->do_remote_wakeup
> +				&& device_may_wakeup(hcd->self.controller)) {
> +
>  			if (t1 & PORT_CONNECT) {
>  				t2 |= PORT_WKOC_E | PORT_WKDISC_E;
>  				t2 &= ~PORT_WKCONN_E;
> 

Looks good to me, thanks for fixing.
I can take it, add the "cc: stable" tag and send it forward to Greg once his trees get updated to 3.16 release candidates

-Mathias