From: Anand Gadiyar <[email protected]>
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 <[email protected]>
Signed-off-by: Santosh Shilimkar <[email protected]>
Acked-by: Kishore Kadiyala <[email protected]>
---
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) {
Jarkko? Tony?
On Tue, 21 Apr 2009 13:09:22 +0530
"Gadiyar, Anand" <[email protected]> wrote:
> From: Anand Gadiyar <[email protected]>
>
> 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 <[email protected]>
> Signed-off-by: Santosh Shilimkar <[email protected]>
> Acked-by: Kishore Kadiyala <[email protected]>
> ---
> 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
WARNING: This correspondence is being monitored by the
Swedish government. Make sure your server uses encryption
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* Pierre Ossman <[email protected]> [090428 12:38]:
> Jarkko? Tony?
Hmm, we haven't heard from Jarkko for a while.. Adrian, care to take
a look at this patch?
Tony
> On Tue, 21 Apr 2009 13:09:22 +0530
> "Gadiyar, Anand" <[email protected]> wrote:
>
> > From: Anand Gadiyar <[email protected]>
> >
> > 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 <[email protected]>
> > Signed-off-by: Santosh Shilimkar <[email protected]>
> > Acked-by: Kishore Kadiyala <[email protected]>
> > ---
> > 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
>
> WARNING: This correspondence is being monitored by the
> Swedish government. Make sure your server uses encryption
> for SMTP traffic and consider using PGP for end-to-end
> encryption.
On Fri, May 22, 2009, Gadiyar, Anand wrote:
> On Wed, May 06, 2009, Gadiyar, Anand wrote:
> > On Tue, May 5, 2009, Jarkko Lavinen wrote:
> > > On Tue, Apr 21, 2009 at 09:39:22AM +0200, ext Gadiyar, Anand wrote:
> > > > From: Anand Gadiyar <[email protected]>
> > > >
> > > > 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.
> > >
> > > I tried the patch with reading from the raw mmc block device to
> > > /dev/null with dd (with bs 32k and 1M). I cannot see any
> > > difference in interrupt count from /proc/interrupts or in read
> > > speed. At least the patch works. Cpu was 34340es3.
> > >
> > > I also trid without the patch just disabling the Buffer
> > > Read/write Ready bits from INT_EN_MASK which is then written to
> > > both MMCHS_IE and MMCHS_ISE. Still no change in read speed nor
> > > mmc irq count.
> > >
> > > Cheers
> > > Jarkko Lavinen
> >
> > I discovered this while doing MMC writes. I did not check if there
> > was any difference during a read. I notice you have only tested with
> > MMC reads.
> >
> > Here's what I get with and without the patch.
> >
> > - Anand
>
>
> Any comments on this? Is it safe to merge?
>
> Thanks,
> Anand
<snip>
Ping?
Patchwork link is:
http://patchwork.kernel.org/patch/19133/