From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH] stmmac: extend DMA initialization delay to 2.5 seconds Date: Thu, 5 Jun 2014 15:30:15 +0100 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-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <1401973080-10085-1-git-send-email-abrodkin@synopsys.com> Sender: linux-kernel-owner@vger.kernel.org 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 List-Id: devicetree@vger.kernel.org +Srinivas and the ST list. > On some platforms existing 100 msecond delay is not enough for DMA bl= ock 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 >=20 > I have a board that requires more than 2 seconds for DMA to zero "res= et" bit. > If for other boards it's still not long enough this value should be e= xtended > once again. >=20 > In the same change I convert "mdelay" to "msleep" to make CPU availab= le for > other processes during DMA init delay which is especially useful in c= ase of > delay for a few seconds. >=20 > Signed-off-by: Alexey Brodkin >=20 > 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(-) >=20 > diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c b/dr= ivers/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 *ioadd= r, int pbl, int fb, int mb, > /* DMA SW reset */ > value |=3D DMA_BUS_MODE_SFT_RESET; > writel(value, ioaddr + DMA_BUS_MODE); > - limit =3D 10; > + limit =3D 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/dri= vers/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 |=3D DMA_BUS_MODE_SFT_RESET; > writel(value, ioaddr + DMA_BUS_MODE); > - limit =3D 10; > + limit =3D 100; > while (limit--) { > if (!(readl(ioaddr + DMA_BUS_MODE) & DMA_BUS_MODE_SFT_RESET)) > break; > - mdelay(10); > + msleep(25); > } > if (limit < 0) > return -EBUSY; --=20 Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org =E2=94=82 Open source software for ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog