From: Grant Likely <grant.likely@secretlab.ca>
To: Jassi Brar <jassisinghbrar@gmail.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>,
David Brownell <dbrownell@users.sourceforge.net>,
Jassi Brar <jassi.brar@samsung.com>,
spi-devel-general@lists.sourceforge.net,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] spi/spi_s3c64xx: Increase dead reckoning time in wait_for_xfer()
Date: Wed, 8 Sep 2010 10:00:34 -0600 [thread overview]
Message-ID: <20100908160034.GB3686@angua.secretlab.ca> (raw)
In-Reply-To: <AANLkTimxXWjiX64wJcNui2mLrvVg9RUtN9fFVnLhZsBY@mail.gmail.com>
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@opensource.wolfsonmicro.com> 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@opensource.wolfsonmicro.com>
> > ---
> > 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@samsung.com>
Applied, thanks.
g.
next prev parent reply other threads:[~2010-09-08 16:00 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-07 15:37 [PATCH 1/2] spi/spi_s3c64xx: Fix timeout handling " Mark Brown
2010-09-07 15:37 ` [PATCH 2/2] spi/spi_s3c64xx: Increase dead reckoning time " Mark Brown
2010-09-08 1:44 ` Jassi Brar
2010-09-08 16:00 ` Grant Likely [this message]
2010-09-08 1:11 ` [PATCH 1/2] spi/spi_s3c64xx: Fix timeout handling " Jassi Brar
2010-09-08 9:06 ` Mark Brown
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20100908160034.GB3686@angua.secretlab.ca \
--to=grant.likely@secretlab.ca \
--cc=broonie@opensource.wolfsonmicro.com \
--cc=dbrownell@users.sourceforge.net \
--cc=jassi.brar@samsung.com \
--cc=jassisinghbrar@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=spi-devel-general@lists.sourceforge.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®