Re: [PATCH 2/2] spi/spi_s3c64xx: Increase dead reckoning time inwait_for_xfer()
From: Grant Likely
Date: Wed Sep 08 2010 - 12:00:41 EST
On Wed, Sep 08, 2010 at 10:44:26AM +0900, Jassi Brar wrote:
> On Wed, Sep 8, 2010 at 12:37 AM, Mark Brown
> <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> > For small transfers at high speeds the expected transfer time can easily
> > be well under 1ms, causing the delay in wait_for_xfer() to be only the
> > dead reckoning fudge factor of 5ms currently included. Experiments on
> > some of my systems shows that this is marginal for some transfers so
> > double it to 10ms.
> >
> > Signed-off-by: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> > ---
> > drivers/spi/spi_s3c64xx.c | 2 +-
> > 1 files changed, 1 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/spi/spi_s3c64xx.c b/drivers/spi/spi_s3c64xx.c
> > index 03b28e4..4abb441 100644
> > --- a/drivers/spi/spi_s3c64xx.c
> > +++ b/drivers/spi/spi_s3c64xx.c
> > @@ -326,7 +326,7 @@ static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd,
> >
> > /* millisecs to xfer 'len' bytes @ 'cur_speed' */
> > ms = xfer->len * 8 * 1000 / sdd->cur_speed;
> > - ms += 5; /* some tolerance */
> > + ms += 10; /* some tolerance */
> >
> > if (dma_mode) {
> > val = msecs_to_jiffies(ms) + 10;
>
> Acked-by: Jassi Brar <jassi.brar@xxxxxxxxxxx>
Applied, thanks.
g.
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