From f92e2f5f889803306e50c06e17ee330403e91b8d Mon Sep 17 00:00:00 2001 From: Mike Miller Date: Wed, 6 Dec 2006 20:35:04 -0800 Subject: [PATCH] [PATCH] cciss: disable DMA prefetch on P600 Unconditionally disable DMA prefetch on the P600 controller. An ASIC bug may result in prefetching beyond the end of physical memory. Signed-off-by: Mike Miller Acked-by: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/cciss.c | 11 +++++++++++ drivers/block/cciss_cmd.h | 1 + 2 files changed, 12 insertions(+) diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c index 4899ab27f78..a17223c43ae 100644 --- a/drivers/block/cciss.c +++ b/drivers/block/cciss.c @@ -3003,6 +3003,17 @@ static int cciss_pci_init(ctlr_info_t *c, struct pci_dev *pdev) } #endif + /* Disabling DMA prefetch for the P600 + * An ASIC bug may result in a prefetch beyond + * physical memory. + */ + if(board_id == 0x3225103C) { + __u32 dma_prefetch; + dma_prefetch = readl(c->vaddr + I2O_DMA1_CFG); + dma_prefetch |= 0x8000; + writel(dma_prefetch, c->vaddr + I2O_DMA1_CFG); + } + #ifdef CCISS_DEBUG printk("Trying to put board into Simple mode\n"); #endif /* CCISS_DEBUG */ diff --git a/drivers/block/cciss_cmd.h b/drivers/block/cciss_cmd.h index 4af7c4c0c7a..b2147cca5ac 100644 --- a/drivers/block/cciss_cmd.h +++ b/drivers/block/cciss_cmd.h @@ -55,6 +55,7 @@ #define I2O_INT_MASK 0x34 #define I2O_IBPOST_Q 0x40 #define I2O_OBPOST_Q 0x44 +#define I2O_DMA1_CFG 0x214 //Configuration Table #define CFGTBL_ChangeReq 0x00000001l -- 2.41.0