diff mbox series

[v2,5/6] mtd: spi-nor: simplify spi_nor_get_flash_info()

Message ID 20240419141249.609534-6-mwalle@kernel.org
State New
Headers show
Series mtd: spi-nor: spring cleaning | expand

Commit Message

Michael Walle April 19, 2024, 2:12 p.m. UTC 
Rework spi_nor_get_flash_info() to make it look more straight forward
and esp. don't return early. The latter is a preparation to check for
deprecated flashes.

Signed-off-by: Michael Walle <mwalle@kernel.org>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
---
 drivers/mtd/spi-nor/core.c | 45 ++++++++++++++++++--------------------
 1 file changed, 21 insertions(+), 24 deletions(-)

Comments

Tudor Ambarus April 22, 2024, 6:41 a.m. UTC | #1 
On 4/19/24 15:12, Michael Walle wrote:
> Rework spi_nor_get_flash_info() to make it look more straight forward
> and esp. don't return early. The latter is a preparation to check for
> deprecated flashes.
> 
> Signed-off-by: Michael Walle <mwalle@kernel.org>
> Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
> ---
>  drivers/mtd/spi-nor/core.c | 45 ++++++++++++++++++--------------------
>  1 file changed, 21 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> index 4e2ae6642d4c..8e4ae1317870 100644
> --- a/drivers/mtd/spi-nor/core.c
> +++ b/drivers/mtd/spi-nor/core.c
> @@ -3294,39 +3294,36 @@ static const struct flash_info *spi_nor_match_name(struct spi_nor *nor,
>  static const struct flash_info *spi_nor_get_flash_info(struct spi_nor *nor,
>  						       const char *name)
>  {
> -	const struct flash_info *info = NULL;
> +	const struct flash_info *jinfo = NULL, *info = NULL;
>  
>  	if (name)
>  		info = spi_nor_match_name(nor, name);
> -	/* Try to auto-detect if chip name wasn't specified or not found */
> -	if (!info)
> -		return spi_nor_detect(nor);
> -
>  	/*
> -	 * If caller has specified name of flash model that can normally be
> -	 * detected using JEDEC, let's verify it.
> +	 * Auto-detect if chip name wasn't specified or not found, or the chip
> +	 * has an ID. If the chip supposedly has an ID, we also do an
> +	 * auto-detection to compare it later.
>  	 */
> -	if (name && info->id) {
> -		const struct flash_info *jinfo;
> -
> +	if (!info || info->id) {
>  		jinfo = spi_nor_detect(nor);
> -		if (IS_ERR(jinfo)) {
> +		if (IS_ERR(jinfo))
>  			return jinfo;
> -		} else if (jinfo != info) {

you can remove else if with if (jinfo != info)

> -			/*
> -			 * JEDEC knows better, so overwrite platform ID. We
> -			 * can't trust partitions any longer, but we'll let
> -			 * mtd apply them anyway, since some partitions may be
> -			 * marked read-only, and we don't want to loose that
> -			 * information, even if it's not 100% accurate.
> -			 */
> -			dev_warn(nor->dev, "found %s, expected %s\n",
> -				 jinfo->name, info->name);

keep the warning where it was
> -			info = jinfo;

move this so that it belongs to if (!info || info->id)
> -		}
>  	}
>

and then return info. Does it work?


	if (name)
		info = spi_nor_match_name(nor, name);

	if (!info || info->id) {
		jinfo = spi_nor_detect(nor);
		if (IS_ERR(jinfo))
			return jinfo;
		
		if (jinfo != info)
			dev_warn(();
		info = jinfo;
	}

	return info;

> -	return info;
> +	/*
> +	 * If caller has specified name of flash model that can normally be
> +	 * detected using JEDEC, let's verify it.
> +	 */
> +	if (info && jinfo && jinfo != info)> +		dev_warn(nor->dev, "found %s, expected %s\n",
> +			 jinfo->name, info->name);
> +
> +	/*
> +	 * JEDEC knows better, so overwrite platform ID. We can't trust
> +	 * partitions any longer, but we'll let mtd apply them anyway, since
> +	 * some partitions may be marked read-only, and we don't want to loose
> +	 * that information, even if it's not 100% accurate.
> +	 */
> +	return jinfo ?: info;
Michael Walle April 22, 2024, 9:53 a.m. UTC | #2 
Hi,

> 	if (name)
> 		info = spi_nor_match_name(nor, name);
>
> 	if (!info || info->id) {
> 		jinfo = spi_nor_detect(nor);
> 		if (IS_ERR(jinfo))
> 			return jinfo;
> 		
> 		if (jinfo != info)

info could be NULL here. So "info &&", apart from that looks good.

> 			dev_warn(();
> 		info = jinfo;
> 	}

Pratyush, should I'll drop your Rb tag then.

-michael
Tudor Ambarus April 22, 2024, 10:12 a.m. UTC | #3 
On 4/22/24 10:53, Michael Walle wrote:
> Hi,
> 
>> 	if (name)
>> 		info = spi_nor_match_name(nor, name);
>>
>> 	if (!info || info->id) {

here

>> 		jinfo = spi_nor_detect(nor);
>> 		if (IS_ERR(jinfo))
>> 			return jinfo;
>> 		
>> 		if (jinfo != info)
> 
> info could be NULL here. So "info &&", apart from that looks good.

it can't be NULL, the parent if indicated above assures info isn't NULL

> 
>> 			dev_warn(();
>> 		info = jinfo;
>> 	}
> 
> Pratyush, should I'll drop your Rb tag then.
> 
> -michael
Tudor Ambarus April 22, 2024, 10:14 a.m. UTC | #4 
On 4/22/24 11:12, Tudor Ambarus wrote:
> 
> 
> On 4/22/24 10:53, Michael Walle wrote:
>> Hi,
>>
>>> 	if (name)
>>> 		info = spi_nor_match_name(nor, name);
>>>
>>> 	if (!info || info->id) {
> 
> here
> 
>>> 		jinfo = spi_nor_detect(nor);
>>> 		if (IS_ERR(jinfo))
>>> 			return jinfo;
>>> 		
>>> 		if (jinfo != info)
>>
>> info could be NULL here. So "info &&", apart from that looks good.
> 
> it can't be NULL, the parent if indicated above assures info isn't NULL

ah, I read it wrong it's if (!info), you're right!

> 
>>
>>> 			dev_warn(();
>>> 		info = jinfo;
>>> 	}
>>
>> Pratyush, should I'll drop your Rb tag then.
>>
>> -michael
diff mbox series

Patch

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 4e2ae6642d4c..8e4ae1317870 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -3294,39 +3294,36 @@  static const struct flash_info *spi_nor_match_name(struct spi_nor *nor,
 static const struct flash_info *spi_nor_get_flash_info(struct spi_nor *nor,
 						       const char *name)
 {
-	const struct flash_info *info = NULL;
+	const struct flash_info *jinfo = NULL, *info = NULL;
 
 	if (name)
 		info = spi_nor_match_name(nor, name);
-	/* Try to auto-detect if chip name wasn't specified or not found */
-	if (!info)
-		return spi_nor_detect(nor);
-
 	/*
-	 * If caller has specified name of flash model that can normally be
-	 * detected using JEDEC, let's verify it.
+	 * Auto-detect if chip name wasn't specified or not found, or the chip
+	 * has an ID. If the chip supposedly has an ID, we also do an
+	 * auto-detection to compare it later.
 	 */
-	if (name && info->id) {
-		const struct flash_info *jinfo;
-
+	if (!info || info->id) {
 		jinfo = spi_nor_detect(nor);
-		if (IS_ERR(jinfo)) {
+		if (IS_ERR(jinfo))
 			return jinfo;
-		} else if (jinfo != info) {
-			/*
-			 * JEDEC knows better, so overwrite platform ID. We
-			 * can't trust partitions any longer, but we'll let
-			 * mtd apply them anyway, since some partitions may be
-			 * marked read-only, and we don't want to loose that
-			 * information, even if it's not 100% accurate.
-			 */
-			dev_warn(nor->dev, "found %s, expected %s\n",
-				 jinfo->name, info->name);
-			info = jinfo;
-		}
 	}
 
-	return info;
+	/*
+	 * If caller has specified name of flash model that can normally be
+	 * detected using JEDEC, let's verify it.
+	 */
+	if (info && jinfo && jinfo != info)
+		dev_warn(nor->dev, "found %s, expected %s\n",
+			 jinfo->name, info->name);
+
+	/*
+	 * JEDEC knows better, so overwrite platform ID. We can't trust
+	 * partitions any longer, but we'll let mtd apply them anyway, since
+	 * some partitions may be marked read-only, and we don't want to loose
+	 * that information, even if it's not 100% accurate.
+	 */
+	return jinfo ?: info;
 }
 
 static u32