[PATCH] mtd: nand: assign mtd->name in find_full_id_nand

[PATCH] mtd: nand: assign mtd->name in find_full_id_nand

[Caizhiyong]

From: Cai Zhiyong <caizhiyong@huawei.com>
Date: Wed, 25 Dec 2013 21:19:21 +0800
Subject: [PATCH] mtd: nand: assign mtd->name in find_full_id_nand

This patch assigned the type->name to mtd->name when mtd->name is
NULL in function "find_full_id_nand".
mtd->name is NULL may cause some problem.

Signed-off-by: Cai Zhiyong <caizhiyong@huawei.com>
---
 drivers/mtd/nand/nand_base.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 9b3bb3c..404e83d 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -3327,6 +3327,9 @@ static bool find_full_id_nand(struct mtd_info *mtd, struct nand_chip *chip,
 
 		*busw = type->options & NAND_BUSWIDTH_16;
 
+		if (!mtd->name)
+			mtd->name = type->name;
+
 		return true;
 	}
 	return false;
-- 
1.8.1.5

Re: [PATCH] mtd: nand: assign mtd->name in find_full_id_nand

[Huang Shijie]

On Thu, Dec 26, 2013 at 01:51:58AM +0000, Caizhiyong wrote:
> From: Cai Zhiyong <caizhiyong@huawei.com>
> Date: Wed, 25 Dec 2013 21:19:21 +0800
> Subject: [PATCH] mtd: nand: assign mtd->name in find_full_id_nand
> 
> This patch assigned the type->name to mtd->name when mtd->name is
> NULL in function "find_full_id_nand".
> mtd->name is NULL may cause some problem.
> 
> Signed-off-by: Cai Zhiyong <caizhiyong@huawei.com>
> ---
>  drivers/mtd/nand/nand_base.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
> index 9b3bb3c..404e83d 100644
> --- a/drivers/mtd/nand/nand_base.c
> +++ b/drivers/mtd/nand/nand_base.c
> @@ -3327,6 +3327,9 @@ static bool find_full_id_nand(struct mtd_info *mtd, struct nand_chip *chip,
>  
>  		*busw = type->options & NAND_BUSWIDTH_16;
>  
> +		if (!mtd->name)
> +			mtd->name = type->name;
> +
>  		return true;
>  	}
>  	return false;
Acked-by: Huang Shijie <b32955@freescale.com>

Re: [PATCH] mtd: nand: assign mtd->name in find_full_id_nand

[Brian Norris]

Hi,

On Thu, Dec 26, 2013 at 10:19:39AM +0800, Huang Shijie wrote:
> On Thu, Dec 26, 2013 at 01:51:58AM +0000, Caizhiyong wrote:
> > From: Cai Zhiyong <caizhiyong@huawei.com>
> > Date: Wed, 25 Dec 2013 21:19:21 +0800
> > Subject: [PATCH] mtd: nand: assign mtd->name in find_full_id_nand
> > 
> > This patch assigned the type->name to mtd->name when mtd->name is
> > NULL in function "find_full_id_nand".
> > mtd->name is NULL may cause some problem.
> > 
> > Signed-off-by: Cai Zhiyong <caizhiyong@huawei.com>
> Acked-by: Huang Shijie <b32955@freescale.com>

Thanks, the patch looks good. Pushed to l2-mtd.git.

Wouldn't this trigger an exception when reading
/sys/class/mtd/mtdX/name? If so, should this be marked for stable?

Brian

RE: [PATCH] mtd: nand: assign mtd->name in find_full_id_nand

[Caizhiyong]

> -----Original Message-----
> From: Brian Norris [mailto:computersforpeace@gmail.com]
> Sent: Sunday, January 12, 2014 4:10 AM
> To: Huang Shijie; Caizhiyong
> Cc: linux-mtd@lists.infradead.org; Wanglin (Albert); David Woodhouse;
> linux-kernel@vger.kernel.org; Artem Bityutskiy
> Subject: Re: [PATCH] mtd: nand: assign mtd->name in find_full_id_nand
> 
> Hi,
> 
> On Thu, Dec 26, 2013 at 10:19:39AM +0800, Huang Shijie wrote:
> > On Thu, Dec 26, 2013 at 01:51:58AM +0000, Caizhiyong wrote:
> > > From: Cai Zhiyong <caizhiyong@huawei.com>
> > > Date: Wed, 25 Dec 2013 21:19:21 +0800
> > > Subject: [PATCH] mtd: nand: assign mtd->name in find_full_id_nand
> > >
> > > This patch assigned the type->name to mtd->name when mtd->name is
> > > NULL in function "find_full_id_nand".
> > > mtd->name is NULL may cause some problem.
> > >
> > > Signed-off-by: Cai Zhiyong <caizhiyong@huawei.com>
> > Acked-by: Huang Shijie <b32955@freescale.com>
> 
> Thanks, the patch looks good. Pushed to l2-mtd.git.
> 
> Wouldn't this trigger an exception when reading
> /sys/class/mtd/mtdX/name? If so, should this be marked for stable?

View the source code, if mtd->name is NULL, cat "/sys/class/mtd/mtdX/name" will get string "(null)".

static ssize_t mtd_name_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_get_drvdata(dev);

	return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
}

Re: [PATCH] mtd: nand: assign mtd->name in find_full_id_nand

[Brian Norris]

On Mon, Jan 13, 2014 at 04:12:45AM +0000, Caizhiyong wrote:
> > -----Original Message-----
> > From: Brian Norris [mailto:computersforpeace@gmail.com]
> > Sent: Sunday, January 12, 2014 4:10 AM
> > 
> > On Thu, Dec 26, 2013 at 10:19:39AM +0800, Huang Shijie wrote:
> > > On Thu, Dec 26, 2013 at 01:51:58AM +0000, Caizhiyong wrote:
> > > > From: Cai Zhiyong <caizhiyong@huawei.com>
> > > > Date: Wed, 25 Dec 2013 21:19:21 +0800
> > > > Subject: [PATCH] mtd: nand: assign mtd->name in find_full_id_nand
> > > >
> > > > This patch assigned the type->name to mtd->name when mtd->name is
> > > > NULL in function "find_full_id_nand".
> > > > mtd->name is NULL may cause some problem.
> > > >
> > > > Signed-off-by: Cai Zhiyong <caizhiyong@huawei.com>
> > > Acked-by: Huang Shijie <b32955@freescale.com>
> > 
> > Thanks, the patch looks good. Pushed to l2-mtd.git.
> > 
> > Wouldn't this trigger an exception when reading
> > /sys/class/mtd/mtdX/name? If so, should this be marked for stable?
> 
> View the source code, if mtd->name is NULL, cat "/sys/class/mtd/mtdX/name" will get string "(null)".
> 
> static ssize_t mtd_name_show(struct device *dev, struct device_attribute *attr, char *buf)
> {
> 	struct mtd_info *mtd = dev_get_drvdata(dev);
> 
> 	return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
> }

Thanks, I forgot that the kernel's printf-like functions handle NULL
pointers gracefully. In that case, this probably doesn't need to be in
-stable.

Brian