Re: [PATCH] OMAP: HSMMC: Do not enable buffer ready interrupt ifusing DMA

From: Pierre Ossman
Date: Tue Apr 28 2009 - 15:38:52 EST


Jarkko? Tony?

On Tue, 21 Apr 2009 13:09:22 +0530
"Gadiyar, Anand" <gadiyar@xxxxxx> wrote:

> From: Anand Gadiyar <gadiyar@xxxxxx>
>
> OMAP: HSMMC: Do not enable buffer ready interrupt if using DMA
>
> This considerably reduces the number of interrupts during a transfer
> and ought to result in some power saving.
>
> Signed-off-by: Anand Gadiyar <gadiyar@xxxxxx>
> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
> Acked-by: Kishore Kadiyala <kishore.kadiyala@xxxxxx>
> ---
> diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
> index e62a22a..2d83807 100644
> --- a/drivers/mmc/host/omap_hsmmc.c
> +++ b/drivers/mmc/host/omap_hsmmc.c
> @@ -70,6 +70,8 @@
> #define DTO_MASK 0x000F0000
> #define DTO_SHIFT 16
> #define INT_EN_MASK 0x307F0033
> +#define BWR_ENABLE (1 << 4)
> +#define BRR_ENABLE (1 << 5)
> #define INIT_STREAM (1 << 1)
> #define DP_SELECT (1 << 21)
> #define DDIR (1 << 4)
> @@ -241,7 +243,12 @@ mmc_omap_start_command(struct mmc_omap_host *host, struct mmc_command *cmd,
> */
> OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR);
> OMAP_HSMMC_WRITE(host->base, ISE, INT_EN_MASK);
> - OMAP_HSMMC_WRITE(host->base, IE, INT_EN_MASK);
> +
> + if (host->use_dma)
> + OMAP_HSMMC_WRITE(host->base, IE,
> + INT_EN_MASK & ~(BRR_ENABLE | BWR_ENABLE));
> + else
> + OMAP_HSMMC_WRITE(host->base, IE, INT_EN_MASK);
>
> host->response_busy = 0;
> if (cmd->flags & MMC_RSP_PRESENT) {


--
-- Pierre Ossman

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