From: Bob Copeland Date: Wed, 15 Apr 2009 11:57:36 +0000 (-0400) Subject: ath5k: manipulate rxlink and descriptor address under rxbuf lock X-Git-Tag: v2.6.31-rc1~330^2~568^2~45 X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=26925042b6b105995ee54c6015e95f0caf9632d6;p=~shefty%2Frdma-dev.git ath5k: manipulate rxlink and descriptor address under rxbuf lock Grabbing an ath5k_buf then dropping the lock is racy because the referenced descriptor can be obtained in another thread and released before the buffer is handed to the hardware. Likewise, manipulating sc->rxlink without the lock can lead to having multiple self-linked hardware descriptors. Changes-licensed-under: 3-Clause-BSD Signed-off-by: Bob Copeland Acked-by: Nick Kossifidis Signed-off-by: John W. Linville --- diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c index 1a6e72fe7be..c8c658bfcf9 100644 --- a/drivers/net/wireless/ath/ath5k/base.c +++ b/drivers/net/wireless/ath/ath5k/base.c @@ -1618,9 +1618,8 @@ ath5k_rx_start(struct ath5k_softc *sc) ATH5K_DBG(sc, ATH5K_DEBUG_RESET, "cachelsz %u rxbufsize %u\n", sc->cachelsz, sc->rxbufsize); - sc->rxlink = NULL; - spin_lock_bh(&sc->rxbuflock); + sc->rxlink = NULL; list_for_each_entry(bf, &sc->rxbuf, list) { ret = ath5k_rxbuf_setup(sc, bf); if (ret != 0) { @@ -1629,9 +1628,9 @@ ath5k_rx_start(struct ath5k_softc *sc) } } bf = list_first_entry(&sc->rxbuf, struct ath5k_buf, list); + ath5k_hw_set_rxdp(ah, bf->daddr); spin_unlock_bh(&sc->rxbuflock); - ath5k_hw_set_rxdp(ah, bf->daddr); ath5k_hw_start_rx_dma(ah); /* enable recv descriptors */ ath5k_mode_setup(sc); /* set filters, etc. */ ath5k_hw_start_rx_pcu(ah); /* re-enable PCU/DMA engine */