From: Ben Dooks <ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org>
To: Dmitry Baryshkov <dbaryshkov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org,
ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org
Subject: Re: [PATCH] i2c-pxa: fix scheduling while atomic in i2c_pxa_abort()
Date: Wed, 6 Aug 2008 23:38:16 +0100 [thread overview]
Message-ID: <20080806223816.GD2716@fluff.org.uk> (raw)
In-Reply-To: <20080805111711.GA4807-nIupHZaCssqR2kOLt6zJ8ErlnG4Plg33XqFh9Ls21Oc@public.gmane.org>
On Tue, Aug 05, 2008 at 03:17:11PM +0400, Dmitry Baryshkov wrote:
> i2c_pxa_abort can be called from the atomic context.
> Change it to use mdelay and counted loop.
if this can be called from an atomic context, is there a distinct
possibility you are going to stop execution of the entire cpu for
the time it takes to sort this out? Is it possible to disable the
interrupt request, fire a work-struct to deal with this and then
re-enabled the controller once it is finished?
> Signed-off-by: Dmitry Baryshkov <dbaryshkov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
> drivers/i2c/busses/i2c-pxa.c | 7 ++++---
> 1 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
> index dde6ce9..9a0f788 100644
> --- a/drivers/i2c/busses/i2c-pxa.c
> +++ b/drivers/i2c/busses/i2c-pxa.c
> @@ -188,14 +188,14 @@ static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
>
> static void i2c_pxa_abort(struct pxa_i2c *i2c)
> {
> - unsigned long timeout = jiffies + HZ/4;
> + int i = 250;
>
> if (i2c_pxa_is_slavemode(i2c)) {
> dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
> return;
> }
>
> - while (time_before(jiffies, timeout) && (readl(_IBMR(i2c)) & 0x1) == 0) {
> + while ((i > 0) && (readl(_IBMR(i2c)) & 0x1) == 0) {
> unsigned long icr = readl(_ICR(i2c));
>
> icr &= ~ICR_START;
> @@ -205,7 +205,8 @@ static void i2c_pxa_abort(struct pxa_i2c *i2c)
>
> show_state(i2c);
>
> - msleep(1);
> + mdelay(1);
> + i --;
> }
>
> writel(readl(_ICR(i2c)) & ~(ICR_MA | ICR_START | ICR_STOP),
> --
> 1.5.6.3
>
>
> --
> With best wishes
> Dmitry
>
>
> _______________________________________________
> i2c mailing list
> i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
> http://lists.lm-sensors.org/mailman/listinfo/i2c
--
Ben (ben-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, http://www.fluff.org/)
'a smiley only costs 4 bytes'
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next prev parent reply other threads:[~2008-08-06 22:38 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-05 11:17 [PATCH] i2c-pxa: fix scheduling while atomic in i2c_pxa_abort() Dmitry Baryshkov
[not found] ` <20080805111711.GA4807-nIupHZaCssqR2kOLt6zJ8ErlnG4Plg33XqFh9Ls21Oc@public.gmane.org>
2008-08-06 22:38 ` Ben Dooks [this message]
2008-08-07 10:12 ` Dmitry Baryshkov
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