From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751589AbaFEOaY (ORCPT ); Thu, 5 Jun 2014 10:30:24 -0400 Received: from mail-ig0-f178.google.com ([209.85.213.178]:43921 "EHLO mail-ig0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751407AbaFEOaW (ORCPT ); Thu, 5 Jun 2014 10:30:22 -0400 Date: Thu, 5 Jun 2014 15:30:15 +0100 From: Lee Jones To: Alexey Brodkin Cc: netdev@vger.kernel.org, "David S. Miller" , Hans de Goede , Giuseppe Cavallaro , Chen-Yu Tsai , linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Vineet Gupta , srinivas.kandagatla@linaro.org, kernel@stlinux.com Subject: Re: [PATCH] stmmac: extend DMA initialization delay to 2.5 seconds Message-ID: <20140605143015.GD24240@lee--X1> References: <1401973080-10085-1-git-send-email-abrodkin@synopsys.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1401973080-10085-1-git-send-email-abrodkin@synopsys.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org +Srinivas and the ST list. > On some platforms existing 100 msecond delay is not enough for DMA block to > recover after reset. This is because MAC DMA waits for all PHY input clocks > to present and depending on the board reset bit deassertion may take much > longer than previously used 100 milliseconds > > I have a board that requires more than 2 seconds for DMA to zero "reset" bit. > If for other boards it's still not long enough this value should be extended > once again. > > In the same change I convert "mdelay" to "msleep" to make CPU available for > other processes during DMA init delay which is especially useful in case of > delay for a few seconds. > > Signed-off-by: Alexey Brodkin > > Cc: David S. Miller > Cc: Hans de Goede > Cc: Giuseppe Cavallaro > Cc: Chen-Yu Tsai > Cc: linux-kernel@vger.kernel.org > Cc: devicetree@vger.kernel.org > Cc: Vineet Gupta > --- > drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c | 4 ++-- > drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c | 4 ++-- > 2 files changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c > index 0c2058a..f713ea7 100644 > --- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c > +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c > @@ -39,11 +39,11 @@ static int dwmac1000_dma_init(void __iomem *ioaddr, int pbl, int fb, int mb, > /* DMA SW reset */ > value |= DMA_BUS_MODE_SFT_RESET; > writel(value, ioaddr + DMA_BUS_MODE); > - limit = 10; > + limit = 100; > while (limit--) { > if (!(readl(ioaddr + DMA_BUS_MODE) & DMA_BUS_MODE_SFT_RESET)) > break; > - mdelay(10); > + msleep(25); > } > if (limit < 0) > return -EBUSY; > diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c > index 7d1dce9..043585f 100644 > --- a/drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c > +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c > @@ -41,11 +41,11 @@ static int dwmac100_dma_init(void __iomem *ioaddr, int pbl, int fb, int mb, > /* DMA SW reset */ > value |= DMA_BUS_MODE_SFT_RESET; > writel(value, ioaddr + DMA_BUS_MODE); > - limit = 10; > + limit = 100; > while (limit--) { > if (!(readl(ioaddr + DMA_BUS_MODE) & DMA_BUS_MODE_SFT_RESET)) > break; > - mdelay(10); > + msleep(25); > } > if (limit < 0) > return -EBUSY; -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog