From c629882ac73cab2cd41d9948caeed633fc570fc0 Mon Sep 17 00:00:00 2001 From: Giuseppe CAVALLARO Date: Fri, 17 Sep 2010 03:23:41 +0000 Subject: [PATCH] stmmac: prevent dma init stuck in case of failures. Add a limit when perform the DMA reset procedure so, in case of problems (i.e. PHY reset failed) the Kernel won't hang on the stmmac DMA initialisation blocking the Kernels execution. Signed-off-by: Giuseppe Cavallaro Signed-off-by: David S. Miller --- drivers/net/stmmac/dwmac1000_dma.c | 10 +++++++++- drivers/net/stmmac/dwmac100_dma.c | 10 +++++++++- 2 files changed, 18 insertions(+), 2 deletions(-) diff --git a/drivers/net/stmmac/dwmac1000_dma.c b/drivers/net/stmmac/dwmac1000_dma.c index 2ef5a56370e9..ce6163e39cd5 100644 --- a/drivers/net/stmmac/dwmac1000_dma.c +++ b/drivers/net/stmmac/dwmac1000_dma.c @@ -33,10 +33,18 @@ static int dwmac1000_dma_init(void __iomem *ioaddr, int pbl, u32 dma_tx, u32 dma_rx) { u32 value = readl(ioaddr + DMA_BUS_MODE); + int limit; + /* DMA SW reset */ value |= DMA_BUS_MODE_SFT_RESET; writel(value, ioaddr + DMA_BUS_MODE); - do {} while ((readl(ioaddr + DMA_BUS_MODE) & DMA_BUS_MODE_SFT_RESET)); + limit = 15000; + while (limit--) { + if (!(readl(ioaddr + DMA_BUS_MODE) & DMA_BUS_MODE_SFT_RESET)) + break; + } + if (limit < 0) + return -EBUSY; value = /* DMA_BUS_MODE_FB | */ DMA_BUS_MODE_4PBL | ((pbl << DMA_BUS_MODE_PBL_SHIFT) | diff --git a/drivers/net/stmmac/dwmac100_dma.c b/drivers/net/stmmac/dwmac100_dma.c index c7279d2b946b..96aac93b789b 100644 --- a/drivers/net/stmmac/dwmac100_dma.c +++ b/drivers/net/stmmac/dwmac100_dma.c @@ -35,10 +35,18 @@ static int dwmac100_dma_init(void __iomem *ioaddr, int pbl, u32 dma_tx, u32 dma_rx) { u32 value = readl(ioaddr + DMA_BUS_MODE); + int limit; + /* DMA SW reset */ value |= DMA_BUS_MODE_SFT_RESET; writel(value, ioaddr + DMA_BUS_MODE); - do {} while ((readl(ioaddr + DMA_BUS_MODE) & DMA_BUS_MODE_SFT_RESET)); + limit = 15000; + while (limit--) { + if (!(readl(ioaddr + DMA_BUS_MODE) & DMA_BUS_MODE_SFT_RESET)) + break; + } + if (limit < 0) + return -EBUSY; /* Enable Application Access by writing to DMA CSR0 */ writel(DMA_BUS_MODE_DEFAULT | (pbl << DMA_BUS_MODE_PBL_SHIFT), -- 2.20.1