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authorAlan Stern <stern@rowland.harvard.edu>2010-01-08 11:18:38 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2010-01-20 18:24:34 -0500
commit49d0f078f494b9d81e820a13dd8093a9bfb0b6b1 (patch)
tree6256ecbc3314bb7e15032e9acbb62a6278f496aa /drivers/usb/host/ehci-hcd.c
parentcec3a53c7fe794237b582e8e77fc0e48465e65ee (diff)
USB: add missing delay during remote wakeup
This patch (as1330) fixes a bug in khbud's handling of remote wakeups. When a device sends a remote-wakeup request, the parent hub (or the host controller driver, for directly attached devices) begins the resume sequence and notifies khubd when the sequence finishes. At this point the port's SUSPEND feature is automatically turned off. However the device needs an additional 10-ms resume-recovery time (TRSMRCY in the USB spec). Khubd does not wait for this delay if the SUSPEND feature is off, and as a result some devices fail to behave properly following a remote wakeup. This patch adds the missing delay to the remote-wakeup path. It also extends the resume-signalling delay used by ehci-hcd and uhci-hcd from 20 ms (the value in the spec) to 25 ms (the value we use for non-remote-wakeup resumes). The extra time appears to help some devices. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: stable <stable@kernel.org> Cc: Rickard Bellini <rickard.bellini@ericsson.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/host/ehci-hcd.c')
-rw-r--r--drivers/usb/host/ehci-hcd.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 5859522d6edd..1ec3857f22e6 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -787,9 +787,10 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
787 787
788 /* start 20 msec resume signaling from this port, 788 /* start 20 msec resume signaling from this port,
789 * and make khubd collect PORT_STAT_C_SUSPEND to 789 * and make khubd collect PORT_STAT_C_SUSPEND to
790 * stop that signaling. 790 * stop that signaling. Use 5 ms extra for safety,
791 * like usb_port_resume() does.
791 */ 792 */
792 ehci->reset_done [i] = jiffies + msecs_to_jiffies (20); 793 ehci->reset_done[i] = jiffies + msecs_to_jiffies(25);
793 ehci_dbg (ehci, "port %d remote wakeup\n", i + 1); 794 ehci_dbg (ehci, "port %d remote wakeup\n", i + 1);
794 mod_timer(&hcd->rh_timer, ehci->reset_done[i]); 795 mod_timer(&hcd->rh_timer, ehci->reset_done[i]);
795 } 796 }