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authorAlan Stern <stern@rowland.harvard.edu>2014-09-02 11:39:15 -0400
committerJiri Kosina <jkosina@suse.cz>2014-09-03 23:37:38 +0200
commit8f507ef522d55a6e2f9e11a1c1163a92756da044 (patch)
tree7f053757c34528cbf56aac2ffc49fe7eb48623eb /drivers/hid
parent79346d620e9de87912de73337f6df8b7f9a46888 (diff)
HID: usbhid: improve handling of Clear-Halt and reset
This patch changes the way usbhid carries out Clear-Halt and reset. Currently, after a Clear-Halt on the interrupt-IN endpoint, the driver immediately restarts the interrupt URB, even if the Clear-Halt failed. This doesn't work out well when the reason for the failure was that the device was disconnected (when a low- or full-speed device is connected through a hub to an EHCI controller, transfer errors caused by disconnection are reported as stalls by the hub). Instead now the driver will attempt a reset after a failed Clear-Halt. The way resets are carried out is also changed. Now the driver will call usb_queue_reset_device() instead of calling usb_reset_device() directly. This avoids a deadlock that would arise when a device is unplugged: The hid_reset() routine runs as a workqueue item, a reset attempt after the device has been unplugged will fail, failure will cause usbhid to be unbound, and the disconnect routine will try to do cancel_work_sync(). The usb_queue_reset_device() implementation is carefully written to handle scenarios like this one properly. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers/hid')
-rw-r--r--drivers/hid/usbhid/hid-core.c34
1 files changed, 9 insertions, 25 deletions
diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index 79cf503e37bf..80c50763b3f8 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -116,40 +116,24 @@ static void hid_reset(struct work_struct *work)
struct usbhid_device *usbhid =
container_of(work, struct usbhid_device, reset_work);
struct hid_device *hid = usbhid->hid;
- int rc = 0;
+ int rc;
if (test_bit(HID_CLEAR_HALT, &usbhid->iofl)) {
dev_dbg(&usbhid->intf->dev, "clear halt\n");
rc = usb_clear_halt(hid_to_usb_dev(hid), usbhid->urbin->pipe);
clear_bit(HID_CLEAR_HALT, &usbhid->iofl);
- hid_start_in(hid);
- }
-
- else if (test_bit(HID_RESET_PENDING, &usbhid->iofl)) {
- dev_dbg(&usbhid->intf->dev, "resetting device\n");
- rc = usb_lock_device_for_reset(hid_to_usb_dev(hid), usbhid->intf);
if (rc == 0) {
- rc = usb_reset_device(hid_to_usb_dev(hid));
- usb_unlock_device(hid_to_usb_dev(hid));
+ hid_start_in(hid);
+ } else {
+ dev_dbg(&usbhid->intf->dev,
+ "clear-halt failed: %d\n", rc);
+ set_bit(HID_RESET_PENDING, &usbhid->iofl);
}
- clear_bit(HID_RESET_PENDING, &usbhid->iofl);
}
- switch (rc) {
- case 0:
- if (!test_bit(HID_IN_RUNNING, &usbhid->iofl))
- hid_io_error(hid);
- break;
- default:
- hid_err(hid, "can't reset device, %s-%s/input%d, status %d\n",
- hid_to_usb_dev(hid)->bus->bus_name,
- hid_to_usb_dev(hid)->devpath,
- usbhid->ifnum, rc);
- /* FALLTHROUGH */
- case -EHOSTUNREACH:
- case -ENODEV:
- case -EINTR:
- break;
+ if (test_bit(HID_RESET_PENDING, &usbhid->iofl)) {
+ dev_dbg(&usbhid->intf->dev, "resetting device\n");
+ usb_queue_reset_device(usbhid->intf);
}
}