From e61dacaeb3918cd00cd642e8fb0828324ac59819 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 8 Sep 2009 17:42:57 -0700 Subject: [PATCH] ioat3: enable dca for completion writes Tag completion writes for direct cache access to reduce the latency of checking for descriptor completions. Signed-off-by: Dan Williams --- drivers/dma/ioat/dma_v3.c | 3 ++- drivers/dma/ioat/registers.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/dma/ioat/dma_v3.c b/drivers/dma/ioat/dma_v3.c index 22af78ec257..0913d11e09e 100644 --- a/drivers/dma/ioat/dma_v3.c +++ b/drivers/dma/ioat/dma_v3.c @@ -167,7 +167,8 @@ static void ioat3_cleanup_tasklet(unsigned long data) struct ioat2_dma_chan *ioat = (void *) data; ioat3_cleanup(ioat); - writew(IOAT_CHANCTRL_RUN, ioat->base.reg_base + IOAT_CHANCTRL_OFFSET); + writew(IOAT_CHANCTRL_RUN | IOAT3_CHANCTRL_COMPL_DCA_EN, + ioat->base.reg_base + IOAT_CHANCTRL_OFFSET); } static void ioat3_restart_channel(struct ioat2_dma_chan *ioat) diff --git a/drivers/dma/ioat/registers.h b/drivers/dma/ioat/registers.h index 85d04b8c563..97d26ea6d72 100644 --- a/drivers/dma/ioat/registers.h +++ b/drivers/dma/ioat/registers.h @@ -84,6 +84,7 @@ /* DMA Channel Registers */ #define IOAT_CHANCTRL_OFFSET 0x00 /* 16-bit Channel Control Register */ #define IOAT_CHANCTRL_CHANNEL_PRIORITY_MASK 0xF000 +#define IOAT3_CHANCTRL_COMPL_DCA_EN 0x0200 #define IOAT_CHANCTRL_CHANNEL_IN_USE 0x0100 #define IOAT_CHANCTRL_DESCRIPTOR_ADDR_SNOOP_CONTROL 0x0020 #define IOAT_CHANCTRL_ERR_INT_EN 0x0010 -- 2.39.3