rt2x00: tune multi-registers I/O timeout

We provide timeout value to rt2x00usb_vendor_request_buff() based on
number of registers to process. That value is passed down to
rt2x00usb_vendor_req_buff_lock() and ends in usb_control_msg(). But we
do not read/write all registers in rt2x00usb_vendor_req_buff_lock() at
once. We read/write them in chunks of 64 bytes in the loop, hence passed
timeout value to low level is too big.

Patch removes timeout argument from rt2x00usb_vendor_request_buff() and
use short REGISTER_TIMEOUT in rt2x00usb_vendor_req_buff_lock(). That
timeout value should be fine for 64 bytes and smaller requests. For
EEPROM read we introduced new timeout value equal to 2 seconds.

Patch fixes process uninterruptible sleep stalls for long period, when
USB bus has problem to satisfy a request and we wait very long time on
usb_start_wait_urb().

Reported-and-tested-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2x00usb.c b/drivers/net/wireless/rt2x00/rt2x00usb.c
index 86c43d1..dc85d3e 100644
--- a/drivers/net/wireless/rt2x00/rt2x00usb.c
+++ b/drivers/net/wireless/rt2x00/rt2x00usb.c
@@ -116,7 +116,7 @@
 int rt2x00usb_vendor_request_buff(struct rt2x00_dev *rt2x00dev,
 				  const u8 request, const u8 requesttype,
 				  const u16 offset, void *buffer,
-				  const u16 buffer_length, const int timeout)
+				  const u16 buffer_length)
 {
 	int status = 0;
 	unsigned char *tb;
@@ -131,7 +131,7 @@
 		bsize = min_t(u16, CSR_CACHE_SIZE, len);
 		status = rt2x00usb_vendor_req_buff_lock(rt2x00dev, request,
 							requesttype, off, tb,
-							bsize, timeout);
+							bsize, REGISTER_TIMEOUT);
 
 		tb  += bsize;
 		len -= bsize;