[PATCH] mtd: nuc900_nand: mark expected switch fall-through

[PATCH] mtd: nuc900_nand: mark expected switch fall-through

[Gustavo A. R. Silva]

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Addresses-Coverity-ID: 1471717 ("Missing break in switch")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 drivers/mtd/nand/raw/nuc900_nand.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/raw/nuc900_nand.c b/drivers/mtd/nand/raw/nuc900_nand.c
index af5b32c9..53a9f6c 100644
--- a/drivers/mtd/nand/raw/nuc900_nand.c
+++ b/drivers/mtd/nand/raw/nuc900_nand.c
@@ -191,8 +191,9 @@ static void nuc900_nand_command_lp(struct mtd_info *mtd, unsigned int command,
 		return;
 
 	case NAND_CMD_READ0:
-
 		write_cmd_reg(nand, NAND_CMD_READSTART);
+		/* fall through */
+
 	default:
 
 		if (!chip->dev_ready) {
-- 
2.7.4

[PATCH] mtd: nuc900_nand: mark expected switch fall-through

[Miquel Raynal]

Hi Gustavo,

Prefix should be "mtd: rawnand: nuc900:"

"Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote on Tue, 10 Jul
2018 08:29:02 -0500:

> In preparation to enabling -Wimplicit-fallthrough, mark switch cases
> where we are expecting to fall through.
> 
> Addresses-Coverity-ID: 1471717 ("Missing break in switch")
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
>  drivers/mtd/nand/raw/nuc900_nand.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/nand/raw/nuc900_nand.c b/drivers/mtd/nand/raw/nuc900_nand.c
> index af5b32c9..53a9f6c 100644
> --- a/drivers/mtd/nand/raw/nuc900_nand.c
> +++ b/drivers/mtd/nand/raw/nuc900_nand.c
> @@ -191,8 +191,9 @@ static void nuc900_nand_command_lp(struct mtd_info *mtd, unsigned int command,
>  		return;
>  
>  	case NAND_CMD_READ0:
> -
>  		write_cmd_reg(nand, NAND_CMD_READSTART);
> +		/* fall through */

Have you checked this is actually the right thing to do?

Thanks,
Miqu?l

[PATCH] mtd: nuc900_nand: mark expected switch fall-through

[Gustavo A. R. Silva]

Hi Miquel,

On 07/18/2018 03:03 AM, Miquel Raynal wrote:
> Hi Gustavo,
> 
> Prefix should be "mtd: rawnand: nuc900:"
> 

Oh OK. I'll fix it.

> "Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote on Tue, 10 Jul
> 2018 08:29:02 -0500:
> 
>> In preparation to enabling -Wimplicit-fallthrough, mark switch cases
>> where we are expecting to fall through.
>>
>> Addresses-Coverity-ID: 1471717 ("Missing break in switch")
>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
>> ---
>>  drivers/mtd/nand/raw/nuc900_nand.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mtd/nand/raw/nuc900_nand.c b/drivers/mtd/nand/raw/nuc900_nand.c
>> index af5b32c9..53a9f6c 100644
>> --- a/drivers/mtd/nand/raw/nuc900_nand.c
>> +++ b/drivers/mtd/nand/raw/nuc900_nand.c
>> @@ -191,8 +191,9 @@ static void nuc900_nand_command_lp(struct mtd_info *mtd, unsigned int command,
>>  		return;
>>  
>>  	case NAND_CMD_READ0:
>> -
>>  		write_cmd_reg(nand, NAND_CMD_READSTART);
>> +		/* fall through */
> 
> Have you checked this is actually the right thing to do?
> 

Actually, no. My first impression was that due to the time this code has been
there, this might be a missing-break false positive. But, now that I'm double
checking, it may well be that this is an actual missing-break bug.

I can send a patch to fix this, but as I'm not familiar with the code, it'd be
of great help if someone could help me to verify this.

Thanks for the feedback.
--
Gustavo

[PATCH] mtd: nuc900_nand: mark expected switch fall-through

[Gustavo A. R. Silva]

Hi Miquel,

On 07/18/2018 03:03 AM, Miquel Raynal wrote:
> Hi Gustavo,
> 
> Prefix should be "mtd: rawnand: nuc900:"
> 

Oh OK. I'll fix it. Thanks.

> "Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote on Tue, 10 Jul
> 2018 08:29:02 -0500:
> 
>> In preparation to enabling -Wimplicit-fallthrough, mark switch cases
>> where we are expecting to fall through.
>>
>> Addresses-Coverity-ID: 1471717 ("Missing break in switch")
>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
>> ---
>>  drivers/mtd/nand/raw/nuc900_nand.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mtd/nand/raw/nuc900_nand.c b/drivers/mtd/nand/raw/nuc900_nand.c
>> index af5b32c9..53a9f6c 100644
>> --- a/drivers/mtd/nand/raw/nuc900_nand.c
>> +++ b/drivers/mtd/nand/raw/nuc900_nand.c
>> @@ -191,8 +191,9 @@ static void nuc900_nand_command_lp(struct mtd_info *mtd, unsigned int command,
>>  		return;
>>  
>>  	case NAND_CMD_READ0:
>> -
>>  		write_cmd_reg(nand, NAND_CMD_READSTART);
>> +		/* fall through */
> 
> Have you checked this is actually the right thing to do?
> 

Actually, no. My first impression was that due to the long time this code has been there,
this might be a missing-break-in-switch false positive. But, due to your comments and a
double check at the code, it may well be that this is an actual bug and that a return
statement should be added after calling write_cmd_reg. Similar to the cases above.

I can send a patch to fix this, but it would be great if someone could help me to verify
this first. :)

Thanks for the feedback!
--
Gustavo