From: Stanislaw Gruszka <sgruszka@redhat.com>
Date: Mon, 19 Mar 2012 14:59:41 +0000 (+0100)
Subject: rt2x00: rt2800usb: fix status register reread logic
X-Git-Tag: firefly_0821_release~3680^2~3154^2~13^2~8
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=4e808a38fdcaeeeddbc05942623279ebe7c02373;p=firefly-linux-kernel-4.4.55.git

rt2x00: rt2800usb: fix status register reread logic

Another good catch from Jakub Kicinski. This patch fixes my
recent commit: ed61e2b02027935520d1be884fac0b2ffce8379a
"rt2x00: rt2800usb: rework txdone code"

We should reread status register only when nobody else start already
reading status i.e. test_and_set_bit(TX_STATUS_READING, flags) return 0.

Reported-by: Jakub Kicinski <moorray@wp.pl>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---

diff --git a/drivers/net/wireless/rt2x00/rt2800usb.c b/drivers/net/wireless/rt2x00/rt2800usb.c
index f97f84606f56..001735f7a661 100644
--- a/drivers/net/wireless/rt2x00/rt2800usb.c
+++ b/drivers/net/wireless/rt2x00/rt2800usb.c
@@ -184,7 +184,7 @@ stop_reading:
 	 * here again if status reading is needed.
 	 */
 	if (rt2800usb_txstatus_pending(rt2x00dev) &&
-	    test_and_set_bit(TX_STATUS_READING, &rt2x00dev->flags))
+	    !test_and_set_bit(TX_STATUS_READING, &rt2x00dev->flags))
 		return true;
 	else
 		return false;