USB: automatically enable RHSC interrupts

This patch (as1069c) changes the way OHCI root-hub status-change
interrupts are enabled.  Currently a special HCD method,
hub_irq_enable(), is called when the hub driver is finished using a
root hub.  This approach turns out to be subject to races, resulting
in unnecessary polling.

The patch does away with the method entirely.  Instead, the driver
automatically enables the RHSC interrupt when no more status changes
are present.  This scheme is safe with controllers using
level-triggered semantics for their interrupt flags.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 0 insertions, 1 deletions

diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c
index 6db7a2889e66..4ed228a89943 100644
--- a/drivers/usb/host/ohci-at91.c
+++ b/drivers/usb/host/ohci-at91.c
@@ -260,7 +260,6 @@ static const struct hc_driver ohci_at91_hc_driver = {
          */
         .hub_status_data =      ohci_hub_status_data,
         .hub_control =          ohci_hub_control,
-        .hub_irq_enable =       ohci_rhsc_enable,
 #ifdef CONFIG_PM
         .bus_suspend =          ohci_bus_suspend,
         .bus_resume =           ohci_bus_resume,