USB: don't explicitly reenable root-hub status interrupts

This patch (as1069b) 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, 9 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 1e23e360ea91..5a338a5d4fe7 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2001,8 +2001,6 @@ int usb_port_resume(struct usb_device *udev)
         }
 
         clear_bit(port1, hub->busy_bits);
-        if (!hub->hdev->parent && !hub->busy_bits[0])
-                usb_enable_root_hub_irq(hub->hdev->bus);
 
         if (status == 0)
                 status = finish_port_resume(udev);
@@ -2918,11 +2916,6 @@ static void hub_events(void)
 
                 hub->activating = 0;
 
-                /* If this is a root hub, tell the HCD it's okay to
-                 * re-enable port-change interrupts now. */
-                if (!hdev->parent && !hub->busy_bits[0])
-                        usb_enable_root_hub_irq(hdev->bus);
-
 loop_autopm:
                 /* Allow autosuspend if we're not going to run again */
                 if (list_empty(&hub->event_list))
@@ -3148,8 +3141,6 @@ int usb_reset_device(struct usb_device *udev)
                         break;
         }
         clear_bit(port1, parent_hub->busy_bits);
-        if (!parent_hdev->parent && !parent_hub->busy_bits[0])
-                usb_enable_root_hub_irq(parent_hdev->bus);
 
         if (ret < 0)
                 goto re_enumerate;