HID: fix a lockup regression when using force feedback on a PID device

Commit 8006479c9b75fb6594a7b746af3d7f1fbb68f18f introduced a spinlock in
input_dev->event_lock, which is locked when handling input events.
However, the hid-pidff driver sleeps when handling events as it waits for
reports being sent to the device before changing the report contents
again.
This causes a system lockup when trying to use force feedback with a PID
device, a regression introduced in 2.6.24 and 2.6.23.15.

Fix it by extracting the raw report data from struct hid_report
immediately when hid_submit_report() is called, therefore allowing
drivers to change the contents of struct hid_report immediately without
affecting the already-queued transfer.

In hid-pidff, re-add the removed usbhid_wait_io() to
pidff_erase_effect() instead, to prevent a full report queue from causing
the submission to fail, thus not freeing up device memory.
pidff_erase_effect() is not called while dev->event_lock is held.

Signed-off-by: Anssi Hannula <anssi.hannula@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/hid/usbhid/usbhid.h b/drivers/hid/usbhid/usbhid.h
index b47f991..abedb13 100644
--- a/drivers/hid/usbhid/usbhid.h
+++ b/drivers/hid/usbhid/usbhid.h
@@ -67,7 +67,7 @@ struct usbhid_device {
 	spinlock_t ctrllock;                                            /* Control fifo spinlock */
 
 	struct urb *urbout;                                             /* Output URB */
-	struct hid_report *out[HID_CONTROL_FIFO_SIZE];                  /* Output pipe fifo */
+	struct hid_output_fifo out[HID_CONTROL_FIFO_SIZE];              /* Output pipe fifo */
 	unsigned char outhead, outtail;                                 /* Output pipe fifo head & tail */
 	char *outbuf;                                                   /* Output buffer */
 	dma_addr_t outbuf_dma;                                          /* Output buffer dma */