[PATCH 3.12 131/175] HID: pidff: Fix initialisation forMicrosoft Sidewinder FF Pro 2

[Jiri Slaby]

From: Jim Keir <jimkeir@xxxxxxxxxxxxxxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit afd700d933963d07391e3e3dfbfbc05e905960ef upstream.

The FF2 driver (usbhid/hid-pidff.c) sends commands to the stick during ff_init.
However, this is called inside a block where driver_input_lock is locked, so
the results of these initial commands are discarded. This behavior is the
"killer", without this nothing else works.

ff_init issues commands using "hid_hw_request". This eventually goes to
hid_input_report, which returns -EBUSY because driver_input_lock is locked. The
change is to delay the ff_init call in hid-core.c until after this lock has
been released.

Calling hid_device_io_start() releases the lock so the device can be
configured.  We also need to call hid_device_io_stop() on exit for the lock to
remain locked while ending the init of the drivers.

[ benjamin.tissoires@xxxxxxxxxx: imrpoved the changelog a lot ]

Signed-off-by: Jim Keir <jimkeir@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Benjamin.tissoires <benjamin.tissoires@xxxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 drivers/hid/usbhid/hid-pidff.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/hid/usbhid/hid-pidff.c b/drivers/hid/usbhid/hid-pidff.c
index 10b616702780..0b531c6a76a5 100644
--- a/drivers/hid/usbhid/hid-pidff.c
+++ b/drivers/hid/usbhid/hid-pidff.c
@@ -1252,6 +1252,8 @@ int hid_pidff_init(struct hid_device *hid)
 
 	pidff->hid = hid;
 
+	hid_device_io_start(hid);
+
 	pidff_find_reports(hid, HID_OUTPUT_REPORT, pidff);
 	pidff_find_reports(hid, HID_FEATURE_REPORT, pidff);
 
@@ -1315,9 +1317,13 @@ int hid_pidff_init(struct hid_device *hid)
 
 	hid_info(dev, "Force feedback for USB HID PID devices by Anssi Hannula <anssi.hannula@xxxxxxxxx>\n");
 
+	hid_device_io_stop(hid);
+
 	return 0;
 
  fail:
+	hid_device_io_stop(hid);
+
 	kfree(pidff);
 	return error;
 }
-- 
2.3.0

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