Return-path: Received: from mail.deathmatch.net ([72.66.92.28]:3419 "EHLO mail.deathmatch.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751941AbZDOL6i (ORCPT ); Wed, 15 Apr 2009 07:58:38 -0400 From: Bob Copeland To: linville@tuxdriver.com, jirislaby@gmail.com, mickflemm@gmail.com, lrodriguez@atheros.com Cc: linux-wireless@vger.kernel.org, ath5k-devel@lists.ath5k.org, Bob Copeland Subject: [PATCH 4/5] ath5k: use rx hw descriptor pointer for self-linked check Date: Wed, 15 Apr 2009 07:57:35 -0400 Message-Id: <1239796656-20646-5-git-send-email-me@bobcopeland.com> (sfid-20090415_135842_781984_FF23300D) In-Reply-To: <1239796656-20646-1-git-send-email-me@bobcopeland.com> References: <1239796656-20646-1-git-send-email-me@bobcopeland.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: This patch simplifies the code used to detect when the self-linked DMA buffer is still in use by hardware, by checking the hardware's rxdp register instead of looking at the software buffer list. Signed-off-by: Bob Copeland --- drivers/net/wireless/ath/ath5k/base.c | 24 ++++-------------------- drivers/net/wireless/ath/ath5k/base.h | 1 - drivers/net/wireless/ath/ath5k/dma.c | 2 -- 3 files changed, 4 insertions(+), 23 deletions(-) diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c index 3bde18f..1a6e72f 100644 --- a/drivers/net/wireless/ath/ath5k/base.c +++ b/drivers/net/wireless/ath/ath5k/base.c @@ -1780,7 +1780,7 @@ ath5k_tasklet_rx(unsigned long data) struct sk_buff *skb, *next_skb; dma_addr_t next_skb_addr; struct ath5k_softc *sc = (void *)data; - struct ath5k_buf *bf, *bf_last; + struct ath5k_buf *bf; struct ath5k_desc *ds; int ret; int hdrlen; @@ -1791,7 +1791,6 @@ ath5k_tasklet_rx(unsigned long data) ATH5K_WARN(sc, "empty rx buf pool\n"); goto unlock; } - bf_last = list_entry(sc->rxbuf.prev, struct ath5k_buf, list); do { rxs.flag = 0; @@ -1800,24 +1799,9 @@ ath5k_tasklet_rx(unsigned long data) skb = bf->skb; ds = bf->desc; - /* - * last buffer must not be freed to ensure proper hardware - * function. When the hardware finishes also a packet next to - * it, we are sure, it doesn't use it anymore and we can go on. - */ - if (bf_last == bf) - bf->flags |= 1; - if (bf->flags) { - struct ath5k_buf *bf_next = list_entry(bf->list.next, - struct ath5k_buf, list); - ret = sc->ah->ah_proc_rx_desc(sc->ah, bf_next->desc, - &rs); - if (ret) - break; - bf->flags &= ~1; - /* skip the overwritten one (even status is martian) */ - goto next; - } + /* bail if HW is still using self-linked descriptor */ + if (ath5k_hw_get_rxdp(sc->ah) == bf->daddr) + break; ret = sc->ah->ah_proc_rx_desc(sc->ah, ds, &rs); if (unlikely(ret == -EINPROGRESS)) diff --git a/drivers/net/wireless/ath/ath5k/base.h b/drivers/net/wireless/ath/ath5k/base.h index 8229561..852b2c1 100644 --- a/drivers/net/wireless/ath/ath5k/base.h +++ b/drivers/net/wireless/ath/ath5k/base.h @@ -56,7 +56,6 @@ struct ath5k_buf { struct list_head list; - unsigned int flags; /* rx descriptor flags */ struct ath5k_desc *desc; /* virtual addr of desc */ dma_addr_t daddr; /* physical addr of desc */ struct sk_buff *skb; /* skbuff for buf */ diff --git a/drivers/net/wireless/ath/ath5k/dma.c b/drivers/net/wireless/ath/ath5k/dma.c index b65b4fe..941b511 100644 --- a/drivers/net/wireless/ath/ath5k/dma.c +++ b/drivers/net/wireless/ath/ath5k/dma.c @@ -80,8 +80,6 @@ int ath5k_hw_stop_rx_dma(struct ath5k_hw *ah) * ath5k_hw_get_rxdp - Get RX Descriptor's address * * @ah: The &struct ath5k_hw - * - * XXX: Is RXDP read and clear ? */ u32 ath5k_hw_get_rxdp(struct ath5k_hw *ah) { -- 1.6.0.6