From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751829AbbCAGJA (ORCPT ); Sun, 1 Mar 2015 01:09:00 -0500 Received: from mail-pa0-f50.google.com ([209.85.220.50]:45698 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751264AbbCAGI4 (ORCPT ); Sun, 1 Mar 2015 01:08:56 -0500 From: Arun Chandran To: David Miller Cc: Nicolas Ferre , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Michal Simek , Arun Chandran Subject: [PATCH 1/2] net: macb: Add on the fly CPU endianness detection Date: Sun, 1 Mar 2015 11:38:02 +0530 Message-Id: <1425190083-16007-1-git-send-email-achandran@mvista.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <20150227.172430.705343480463996651.davem@davemloft.net> References: <20150227.172430.705343480463996651.davem@davemloft.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Program management descriptor's access mode according to the dynamically detected CPU endianness. Signed-off-by: Arun Chandran Acked-by: Nicolas Ferre Tested-by: Michal Simek --- * Adding CPU endianness detection according to Michal Simek * Added Acked-by: Nicolas Ferre * Added Tested-by: Michal Simek --- --- drivers/net/ethernet/cadence/macb.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c index 05fb36d..1fe8b94 100644 --- a/drivers/net/ethernet/cadence/macb.c +++ b/drivers/net/ethernet/cadence/macb.c @@ -1578,6 +1578,7 @@ static u32 macb_dbw(struct macb *bp) static void macb_configure_dma(struct macb *bp) { u32 dmacfg; + u32 tmp, ncr; if (macb_is_gem(bp)) { dmacfg = gem_readl(bp, DMACFG) & ~GEM_BF(RXBS, -1L); @@ -1586,10 +1587,23 @@ static void macb_configure_dma(struct macb *bp) dmacfg = GEM_BFINS(FBLDO, bp->dma_burst_length, dmacfg); dmacfg |= GEM_BIT(TXPBMS) | GEM_BF(RXBMS, -1L); dmacfg &= ~GEM_BIT(ENDIA_PKT); - /* Tell the chip to byteswap descriptors on big-endian hosts */ -#ifdef __BIG_ENDIAN - dmacfg |= GEM_BIT(ENDIA_DESC); -#endif + + /* Find the CPU endianness by using the loopback bit of net_ctrl + * register. save it first. When the CPU is in big endian we + * need to program swaped mode for management descriptor access. + */ + ncr = macb_readl(bp, NCR); + __raw_writel(MACB_BIT(LLB), bp->regs + MACB_NCR); + tmp = __raw_readl(bp->regs + MACB_NCR); + + if (tmp == MACB_BIT(LLB)) + dmacfg &= ~GEM_BIT(ENDIA_DESC); + else + dmacfg |= GEM_BIT(ENDIA_DESC); /* CPU in big endian */ + + /* Restore net_ctrl */ + macb_writel(bp, NCR, ncr); + if (bp->dev->features & NETIF_F_HW_CSUM) dmacfg |= GEM_BIT(TXCOEN); else -- 1.9.1