Return-path: Received: from he.sipsolutions.net ([78.46.109.217]:42212 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751455Ab2LJVs5 (ORCPT ); Mon, 10 Dec 2012 16:48:57 -0500 From: Johannes Berg To: linux-wireless@vger.kernel.org Cc: Emmanuel Grumbach Subject: [PATCH 01/10] iwlwifi: read the Rx write pointer only once Date: Mon, 10 Dec 2012 22:49:09 +0100 Message-Id: <1355176158-24675-1-git-send-email-johannes@sipsolutions.net> (sfid-20121210_224900_482256_E108B542) In-Reply-To: <1355176087.8083.17.camel@jlt4.sipsolutions.net> References: <1355176087.8083.17.camel@jlt4.sipsolutions.net> Sender: linux-wireless-owner@vger.kernel.org List-ID: From: Emmanuel Grumbach The FH (DMA engine) tells the driver the index of the last ready (closed) Rx buffer. This data is in closed_rb_num. If we read this data several times we may get inconsistencies between the code and the debug prints which can make it harder to debug issues here. Signed-off-by: Emmanuel Grumbach Signed-off-by: Johannes Berg --- drivers/net/wireless/iwlwifi/pcie/rx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/wireless/iwlwifi/pcie/rx.c b/drivers/net/wireless/iwlwifi/pcie/rx.c index c81b978..787b9ca 100644 --- a/drivers/net/wireless/iwlwifi/pcie/rx.c +++ b/drivers/net/wireless/iwlwifi/pcie/rx.c @@ -698,7 +698,7 @@ static void iwl_pcie_rx_handle(struct iwl_trans *trans) /* uCode's read index (stored in shared DRAM) indicates the last Rx * buffer that the driver may process (last buffer filled by ucode). */ - r = le16_to_cpu(rxq->rb_stts->closed_rb_num) & 0x0FFF; + r = le16_to_cpu(ACCESS_ONCE(rxq->rb_stts->closed_rb_num)) & 0x0FFF; i = rxq->read; /* Rx interrupt, but nothing sent from uCode */ -- 1.8.0