2014-04-11 22:23:35

by Doug Anderson

Subject: [PATCH] i2c: s3c2410: resume race fix

From: Olof Johansson <[email protected]>

Don't unmark the device as suspended until after it's been re-setup.

The main race would be w.r.t. an i2c driver that gets resumed at the same
time (asyncronously), that is allowed to do a transfer since suspended
is set to 0 before reinit, but really should have seen the -EIO return
instead.

Signed-off-by: Olof Johansson <[email protected]>
Signed-off-by: Doug Anderson <[email protected]>
---
drivers/i2c/busses/i2c-s3c2410.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index ae44910..bb3a996 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -1276,10 +1276,10 @@ static int s3c24xx_i2c_resume(struct device *dev)
struct platform_device *pdev = to_platform_device(dev);
struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);

- i2c->suspended = 0;
clk_prepare_enable(i2c->clk);
s3c24xx_i2c_init(i2c);
clk_disable_unprepare(i2c->clk);
+ i2c->suspended = 0;

return 0;
}
--
1.9.1.423.g4596e3a

2014-04-23 09:50:28

by Kukjin Kim

Subject: RE: [PATCH] i2c: s3c2410: resume race fix

Doug Anderson wrote:
>
> From: Olof Johansson <[email protected]>
>
> Don't unmark the device as suspended until after it's been re-setup.
>
> The main race would be w.r.t. an i2c driver that gets resumed at the same
> time (asyncronously), that is allowed to do a transfer since suspended
> is set to 0 before reinit, but really should have seen the -EIO return
> instead.
>
> Signed-off-by: Olof Johansson <[email protected]>
> Signed-off-by: Doug Anderson <[email protected]>

Acked-by: Kukjin Kim <[email protected]>

Thanks,
Kukjin

> ---
> drivers/i2c/busses/i2c-s3c2410.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-
> s3c2410.c
> index ae44910..bb3a996 100644
> --- a/drivers/i2c/busses/i2c-s3c2410.c
> +++ b/drivers/i2c/busses/i2c-s3c2410.c
> @@ -1276,10 +1276,10 @@ static int s3c24xx_i2c_resume(struct device *dev)
> struct platform_device *pdev = to_platform_device(dev);
> struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
>
> - i2c->suspended = 0;
> clk_prepare_enable(i2c->clk);
> s3c24xx_i2c_init(i2c);
> clk_disable_unprepare(i2c->clk);
> + i2c->suspended = 0;
>
> return 0;
> }
> --
> 1.9.1.423.g4596e3a