linux-kernel - Re: [PATCH] media: cxd2099: move pre-init values out of init()

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Message-ID: <20150408080903.1fdc7c4e@recife.lan>
Date:	Wed, 8 Apr 2015 08:09:03 -0300
From:	Mauro Carvalho Chehab <mchehab@....samsung.com>
To:	luisbg <luis@...ethencourt.com>
Cc:	linux-media@...r.kernel.org, devel@...verdev.osuosl.org,
	linux-kernel@...r.kernel.org, gregkh@...uxfoundation.org
Subject: Re: [PATCH] media: cxd2099: move pre-init values out of init()

Em Sun, 8 Feb 2015 20:55:36 +0000
luisbg <luis@...ethencourt.com> escreveu:

> Improve code readability by moving out all pre-init values from the init
> function.
> 
> Signed-off-by: Luis de Bethencourt <luis.bg@...sung.com>
> ---
>  drivers/staging/media/cxd2099/cxd2099.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/media/cxd2099/cxd2099.c b/drivers/staging/media/cxd2099/cxd2099.c
> index 657ea48..bafe36f 100644
> --- a/drivers/staging/media/cxd2099/cxd2099.c
> +++ b/drivers/staging/media/cxd2099/cxd2099.c
> @@ -300,7 +300,6 @@ static int init(struct cxd *ci)
>  	int status;
>  
>  	mutex_lock(&ci->lock);
> -	ci->mode = -1;
>  	do {
>  		status = write_reg(ci, 0x00, 0x00);
>  		if (status < 0)
> @@ -420,7 +419,6 @@ static int init(struct cxd *ci)
>  		status = write_regm(ci, 0x09, 0x08, 0x08);
>  		if (status < 0)
>  			break;
> -		ci->cammode = -1;
>  		cam_mode(ci, 0);
>  	} while (0);
>  	mutex_unlock(&ci->lock);
> @@ -711,6 +709,8 @@ struct dvb_ca_en50221 *cxd2099_attach(struct cxd2099_cfg *cfg,
>  
>  	ci->en = en_templ;
>  	ci->en.data = ci;
> +	ci->mode = -1;
> +	ci->cammode = -1;

This actually changes the logic, as, cammode is == -1 only if the
do {} while loop succeeds.

Also, calling cam_mode(ci, 0) will change cammode to 0. Btw, for
it to work, ci->mode should be initialized earlier.

So, this patch looks very wrong on my eyes, except if you found
a real bug on it.

Have you tested it on a real device? What bug does it fix?

Regards,
Mauro

>  	init(ci);
>  	dev_info(&i2c->dev, "Attached CXD2099AR at %02x\n", ci->cfg.adr);
>  	return &ci->en;
--
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