[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20080711151919.9cda44ea.akpm@linux-foundation.org>
Date: Fri, 11 Jul 2008 15:19:19 -0700
From: Andrew Morton <akpm@...ux-foundation.org>
To: Andres Salomon <dilinger@...ued.net>
Cc: linux-kernel@...r.kernel.org,
Cortland Setlow <csetlow@...er-research.com>, corbet@....net,
video4linux-list@...hat.com,
Mauro Carvalho Chehab <mchehab@...radead.org>
Subject: Re: [PATCH resend] ov7670: clean up ov7670_read semantics
On Fri, 11 Jul 2008 16:52:16 -0400 Andres Salomon <dilinger@...ued.net> wrote:
> [note: this should probably go in for 2.6.26, as it fixes a bug in
> ov7670_s_fmt where we incorrectly think that we've failed because we
> return !0]
>
In which case 2.6.25.x wants the fix as well?
>
> Cortland Setlow pointed out a bug in ov7670.c where the result from
> ov7670_read() was just being checked for !0, rather than <0. This
> made me realize that ov7670_read's semantics were rather confusing;
> it both fills in 'value' with the result, and returns it. This is
> goes against general kernel convention; so rather than fixing callers,
> let's fix the function.
>
> This makes ov7670_read return <0 in the case of an error, and 0 upon
> success. Thus, code like:
>
> res = ov7670_read(...);
> if (!res)
> goto error;
>
> ..will work properly.
>
> Signed-off-by: Cortland Setlow <csetlow@...er-research.com>
> Signed-off-by: Andres Salomon <dilinger@...ian.org>
> Acked-by: Jonathan Corbet <corbet@....net>
> ---
> drivers/media/video/ov7670.c | 4 +++-
> 1 files changed, 3 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/media/video/ov7670.c b/drivers/media/video/ov7670.c
> index 2bc6bdc..d7bfd30 100644
> --- a/drivers/media/video/ov7670.c
> +++ b/drivers/media/video/ov7670.c
> @@ -406,8 +406,10 @@ static int ov7670_read(struct i2c_client *c,
> unsigned char reg, int ret;
You have some wordwrapping happening there.
> ret = i2c_smbus_read_byte_data(c, reg);
> - if (ret >= 0)
> + if (ret >= 0) {
> *value = (unsigned char) ret;
> + ret = 0;
> + }
> return ret;
> }
>
> --
> 1.5.5.3
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists