diff options
author | Alan Stern <stern@rowland.harvard.edu> | 2014-09-02 19:39:15 +0400 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2014-09-04 01:37:38 +0400 |
commit | 8f507ef522d55a6e2f9e11a1c1163a92756da044 (patch) | |
tree | 7f053757c34528cbf56aac2ffc49fe7eb48623eb /drivers/hid | |
parent | 79346d620e9de87912de73337f6df8b7f9a46888 (diff) | |
download | linux-8f507ef522d55a6e2f9e11a1c1163a92756da044.tar.xz |
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.c | 34 |
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); } } |