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authorSarah Sharp <sarah.a.sharp@linux.intel.com>2011-11-12 02:57:33 +0400
committerSarah Sharp <sarah.a.sharp@linux.intel.com>2012-02-15 00:12:22 +0400
commit623bef9e03a60adc623b09673297ca7a1cdfb367 (patch)
treee6a7a90af43d6f091874a036275bf01b155e36b6 /drivers/usb/host/xhci-mem.c
parentd93814cfadb131fb219359d4b7008c728421c552 (diff)
downloadlinux-623bef9e03a60adc623b09673297ca7a1cdfb367.tar.xz
USB/xhci: Enable remote wakeup for USB3 devices.
When the USB 3.0 hub support went in, I disabled selective suspend for all external USB 3.0 hubs because they used a different mechanism to enable remote wakeup. In fact, other USB 3.0 devices that could signal remote wakeup would have been prevented from going into suspend because they would have stalled the SetFeature Device Remote Wakeup request. This patch adds support for the USB 3.0 way of enabling remote wake up (with a SetFeature Function Suspend request), and enables selective suspend for all hubs during hub_probe. It assumes that all USB 3.0 have only one "function" as defined by the interface association descriptor, which is true of all the USB 3.0 devices I've seen so far. FIXME if that turns out to change later. After a device signals a remote wakeup, it is supposed to send a Device Notification packet to the host controller, signaling which function sent the remote wakeup. The host can then put any other functions back into function suspend. Since we don't have support for function suspend (and no devices currently support it), we'll just assume the hub function will resume the device properly when it received the port status change notification, and simply ignore any device notification events from the xHCI host controller. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Diffstat (limited to 'drivers/usb/host/xhci-mem.c')
-rw-r--r--drivers/usb/host/xhci-mem.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 36cbe2226a44..6b70e7fb484c 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -2141,7 +2141,7 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
unsigned int val, val2;
u64 val_64;
struct xhci_segment *seg;
- u32 page_size;
+ u32 page_size, temp;
int i;
page_size = xhci_readl(xhci, &xhci->op_regs->page_size);
@@ -2324,6 +2324,15 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
INIT_LIST_HEAD(&xhci->lpm_failed_devs);
+ /* Enable USB 3.0 device notifications for function remote wake, which
+ * is necessary for allowing USB 3.0 devices to do remote wakeup from
+ * U3 (device suspend).
+ */
+ temp = xhci_readl(xhci, &xhci->op_regs->dev_notification);
+ temp &= ~DEV_NOTE_MASK;
+ temp |= DEV_NOTE_FWAKE;
+ xhci_writel(xhci, temp, &xhci->op_regs->dev_notification);
+
return 0;
fail: