[PATCH v2 1/4] mtd: core: provide unique name for nvmem device, take two

[PATCH v2 1/4] mtd: core: provide unique name for nvmem device, take two

[Michael Walle]

Commit c048b60d39e1 ("mtd: core: provide unique name for nvmem device")
tries to give the nvmem device a unique name, but fails badly if the mtd
device doesn't have a "struct device" associated with it, i.e. if
CONFIG_MTD_PARTITIONED_MASTER is not set. This will result in the name
"(null)-user-otp", which is not unique. It seems the best we can do is
to use the compatible name together with a unique identifier added by
the nvmem subsystem by using NVMEM_DEVID_AUTO.

Fixes: c048b60d39e1 ("mtd: core: provide unique name for nvmem device")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Walle <michael@walle.cc>
---
v2:
 - actually use NVMEM_DEVID_AUTO as described in the commit message

 drivers/mtd/mtdcore.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 0feacb9fbdac..8fc66cda4a09 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -888,8 +888,8 @@ static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd,
 
 	/* OTP nvmem will be registered on the physical device */
 	config.dev = mtd->dev.parent;
-	config.name = kasprintf(GFP_KERNEL, "%s-%s", dev_name(&mtd->dev), compatible);
-	config.id = NVMEM_DEVID_NONE;
+	config.name = compatible;
+	config.id = NVMEM_DEVID_AUTO;
 	config.owner = THIS_MODULE;
 	config.type = NVMEM_TYPE_OTP;
 	config.root_only = true;
@@ -905,7 +905,6 @@ static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd,
 		nvmem = NULL;
 
 	of_node_put(np);
-	kfree(config.name);
 
 	return nvmem;
 }
-- 
2.30.2

[PATCH v2 2/4] mtd: core: fix nvmem error reporting

[Michael Walle]

The master MTD will only have an associated device if
CONFIG_MTD_PARTITIONED_MASTER is set, thus we cannot use dev_err() on
mtd->dev. Instead use the parent device which is the physical flash
memory.

Fixes: 4b361cfa8624 ("mtd: core: add OTP nvmem provider support")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Walle <michael@walle.cc>
---
v2:
 - none

 drivers/mtd/mtdcore.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 8fc66cda4a09..c38a13cb8d5e 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -939,6 +939,7 @@ static int mtd_nvmem_fact_otp_reg_read(void *priv, unsigned int offset,
 
 static int mtd_otp_nvmem_add(struct mtd_info *mtd)
 {
+	struct device *dev = mtd->dev.parent;
 	struct nvmem_device *nvmem;
 	ssize_t size;
 	int err;
@@ -952,7 +953,7 @@ static int mtd_otp_nvmem_add(struct mtd_info *mtd)
 			nvmem = mtd_otp_nvmem_register(mtd, "user-otp", size,
 						       mtd_nvmem_user_otp_reg_read);
 			if (IS_ERR(nvmem)) {
-				dev_err(&mtd->dev, "Failed to register OTP NVMEM device\n");
+				dev_err(dev, "Failed to register OTP NVMEM device\n");
 				return PTR_ERR(nvmem);
 			}
 			mtd->otp_user_nvmem = nvmem;
@@ -970,7 +971,7 @@ static int mtd_otp_nvmem_add(struct mtd_info *mtd)
 			nvmem = mtd_otp_nvmem_register(mtd, "factory-otp", size,
 						       mtd_nvmem_fact_otp_reg_read);
 			if (IS_ERR(nvmem)) {
-				dev_err(&mtd->dev, "Failed to register OTP NVMEM device\n");
+				dev_err(dev, "Failed to register OTP NVMEM device\n");
 				err = PTR_ERR(nvmem);
 				goto err;
 			}
-- 
2.30.2

[PATCH v2 3/4] mtd: core: fix error path for nvmem provider

[Michael Walle]

If mtd_otp_nvmem_add() fails, the partitions won't be removed
because there is simply no call to del_mtd_partitions().
Unfortunately, add_mtd_partitions() will print all partitions to
the kernel console. If mtd_otp_nvmem_add() returns -EPROBE_DEFER
this would print the partitions multiple times to the kernel
console. Instead move mtd_otp_nvmem_add() to the beginning of the
function.

Fixes: 4b361cfa8624 ("mtd: core: add OTP nvmem provider support")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Walle <michael@walle.cc>
---
v2:
 - none

 drivers/mtd/mtdcore.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index c38a13cb8d5e..0bc9676fe029 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -1023,10 +1023,14 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
 
 	mtd_set_dev_defaults(mtd);
 
+	ret = mtd_otp_nvmem_add(mtd);
+	if (ret)
+		goto out;
+
 	if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
 		ret = add_mtd_device(mtd);
 		if (ret)
-			return ret;
+			goto out;
 	}
 
 	/* Prefer parsed partitions over driver-provided fallback */
@@ -1061,9 +1065,12 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
 		register_reboot_notifier(&mtd->reboot_notifier);
 	}
 
-	ret = mtd_otp_nvmem_add(mtd);
-
 out:
+	if (ret) {
+		nvmem_unregister(mtd->otp_user_nvmem);
+		nvmem_unregister(mtd->otp_factory_nvmem);
+	}
+
 	if (ret && device_is_registered(&mtd->dev))
 		del_mtd_device(mtd);
 
-- 
2.30.2

[PATCH v2 4/4] mtd: core: prepare mtd_otp_nvmem_add() to handle -EPROBE_DEFER

[Michael Walle]

NVMEM soon will get the ability for nvmem layouts and these might
not be ready when nvmem_register() is called and thus it might
return -EPROBE_DEFER. Don't print the error message in this case.

Signed-off-by: Michael Walle <michael@walle.cc>
---
v2:
 - none

 drivers/mtd/mtdcore.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 0bc9676fe029..83a22566a8ce 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -953,8 +953,8 @@ static int mtd_otp_nvmem_add(struct mtd_info *mtd)
 			nvmem = mtd_otp_nvmem_register(mtd, "user-otp", size,
 						       mtd_nvmem_user_otp_reg_read);
 			if (IS_ERR(nvmem)) {
-				dev_err(dev, "Failed to register OTP NVMEM device\n");
-				return PTR_ERR(nvmem);
+				err = PTR_ERR(nvmem);
+				goto err;
 			}
 			mtd->otp_user_nvmem = nvmem;
 		}
@@ -971,7 +971,6 @@ static int mtd_otp_nvmem_add(struct mtd_info *mtd)
 			nvmem = mtd_otp_nvmem_register(mtd, "factory-otp", size,
 						       mtd_nvmem_fact_otp_reg_read);
 			if (IS_ERR(nvmem)) {
-				dev_err(dev, "Failed to register OTP NVMEM device\n");
 				err = PTR_ERR(nvmem);
 				goto err;
 			}
@@ -983,7 +982,7 @@ static int mtd_otp_nvmem_add(struct mtd_info *mtd)
 
 err:
 	nvmem_unregister(mtd->otp_user_nvmem);
-	return err;
+	return dev_err_probe(dev, err, "Failed to register OTP NVMEM device\n");
 }
 
 /**
-- 
2.30.2

Re: [PATCH v2 1/4] mtd: core: provide unique name for nvmem device, take two

[Miquel Raynal]

Hi Michael,

michael@walle.cc wrote on Wed,  8 Mar 2023 09:20:18 +0100:

> Commit c048b60d39e1 ("mtd: core: provide unique name for nvmem device")
> tries to give the nvmem device a unique name, but fails badly if the mtd
> device doesn't have a "struct device" associated with it, i.e. if
> CONFIG_MTD_PARTITIONED_MASTER is not set. This will result in the name
> "(null)-user-otp", which is not unique. It seems the best we can do is
> to use the compatible name together with a unique identifier added by
> the nvmem subsystem by using NVMEM_DEVID_AUTO.
> 
> Fixes: c048b60d39e1 ("mtd: core: provide unique name for nvmem device")
> Cc: stable@vger.kernel.org
> Signed-off-by: Michael Walle <michael@walle.cc>
> ---
> v2:
>  - actually use NVMEM_DEVID_AUTO as described in the commit message
> 

Thanks for the v2, as I want to share a clean immutable branch with
Greg, I made an exception in force pushing this patch in place of its
v1 counterpart.

>  drivers/mtd/mtdcore.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> index 0feacb9fbdac..8fc66cda4a09 100644
> --- a/drivers/mtd/mtdcore.c
> +++ b/drivers/mtd/mtdcore.c
> @@ -888,8 +888,8 @@ static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd,
>  
>  	/* OTP nvmem will be registered on the physical device */
>  	config.dev = mtd->dev.parent;
> -	config.name = kasprintf(GFP_KERNEL, "%s-%s", dev_name(&mtd->dev), compatible);
> -	config.id = NVMEM_DEVID_NONE;
> +	config.name = compatible;
> +	config.id = NVMEM_DEVID_AUTO;
>  	config.owner = THIS_MODULE;
>  	config.type = NVMEM_TYPE_OTP;
>  	config.root_only = true;
> @@ -905,7 +905,6 @@ static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd,
>  		nvmem = NULL;
>  
>  	of_node_put(np);
> -	kfree(config.name);
>  
>  	return nvmem;
>  }


Thanks,
Miquèl