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 f97f846..001735f 100644 (file)
--- 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;