Message ID | 1401973080-10085-1-git-send-email-abrodkin@synopsys.com |
---|---|
State | Changes Requested, archived |
Delegated to: | David Miller |
Headers | show |
+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 <abrodkin@synopsys.com> > > Cc: David S. Miller <davem@davemloft.net> > Cc: Hans de Goede <hdegoede@redhat.com> > Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com> > Cc: Chen-Yu Tsai <wens@csie.org> > Cc: linux-kernel@vger.kernel.org > Cc: devicetree@vger.kernel.org > Cc: Vineet Gupta <vgupta@synopsys.com> > --- > 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;
From: Alexey Brodkin <Alexey.Brodkin@synopsys.com> Date: Thu, 5 Jun 2014 16:58:00 +0400 > 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 <abrodkin@synopsys.com> This will not work, you cannot sleep with spinlocks held, and this code is absolutely called in such a context. For example stmmac_resume() --> stmmac_hw_setup() -> stmmac_init_dma_engine(). stmmac_resume() holds priv->lock over all of these operations, and even has interrupts disabled. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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;
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 <abrodkin@synopsys.com> Cc: David S. Miller <davem@davemloft.net> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com> Cc: Chen-Yu Tsai <wens@csie.org> Cc: linux-kernel@vger.kernel.org Cc: devicetree@vger.kernel.org Cc: Vineet Gupta <vgupta@synopsys.com> --- 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(-)