From mboxrd@z Thu Jan 1 00:00:00 1970 From: Troy Kisky Subject: [PATCH net-next V2 3/8] net: fec: fix fec_enet_get_free_txdesc_num Date: Fri, 5 Feb 2016 14:52:45 -0700 Message-ID: <1454709170-19527-4-git-send-email-troy.kisky@boundarydevices.com> References: <1454709170-19527-1-git-send-email-troy.kisky@boundarydevices.com> Cc: fabio.estevam@freescale.com, l.stach@pengutronix.de, andrew@lunn.ch, tremyfr@gmail.com, linux@arm.linux.org.uk, linux-arm-kernel@lists.infradead.org, laci@boundarydevices.com, shawnguo@kernel.org, johannes@sipsolutions.net, arnd@arndb.de, Troy Kisky To: netdev@vger.kernel.org, davem@davemloft.net, B38611@freescale.com Return-path: Received: from mail-pf0-f182.google.com ([209.85.192.182]:33820 "EHLO mail-pf0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751123AbcBEVzK (ORCPT ); Fri, 5 Feb 2016 16:55:10 -0500 Received: by mail-pf0-f182.google.com with SMTP id o185so75229516pfb.1 for ; Fri, 05 Feb 2016 13:55:09 -0800 (PST) In-Reply-To: <1454709170-19527-1-git-send-email-troy.kisky@boundarydevices.com> Sender: netdev-owner@vger.kernel.org List-ID: When first initialized, cur_tx points to the 1st entry in the queue, and dirty_tx points to the last. At this point, fec_enet_get_free_txdesc_num will return tx_ring_size -2. If tx_ring_size -2 entries are now queued, then fec_enet_get_free_txdesc_num should return 0, but it returns tx_ring_size instead. Signed-off-by: Troy Kisky --- drivers/net/ethernet/freescale/fec_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 162fa59..adbddfd 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -296,7 +296,7 @@ static int fec_enet_get_free_txdesc_num(struct fec_enet_private *fep, entries = ((const char *)txq->dirty_tx - (const char *)txq->cur_tx) / fep->bufdesc_size - 1; - return entries > 0 ? entries : entries + txq->tx_ring_size; + return entries >= 0 ? entries : entries + txq->tx_ring_size; } static void swap_buffer(void *bufaddr, int len) -- 2.5.0