diff mbox series

[v1] mtd: rawnand: meson: handle OOB buffer according OOB layout

Message ID 20231109053953.3863664-1-avkrasnov@salutedevices.com (mailing list archive)
State New, archived
Headers show
Series [v1] mtd: rawnand: meson: handle OOB buffer according OOB layout | expand

Commit Message

Arseniy Krasnov Nov. 9, 2023, 5:39 a.m. UTC
In case of MTD_OPS_AUTO_OOB mode, MTD/NAND layer fills/reads OOB buffer
according current OOB layout so we need to follow it in the driver.

Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
---
 drivers/mtd/nand/raw/meson_nand.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Viacheslav Nov. 9, 2023, 8:06 a.m. UTC | #1
Hi!

On Thu, 2023-11-09 at 08:39 +0300, Arseniy Krasnov wrote:
> In case of MTD_OPS_AUTO_OOB mode, MTD/NAND layer fills/reads OOB buffer
> according current OOB layout so we need to follow it in the driver.
> 
> Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
> ---
>  drivers/mtd/nand/raw/meson_nand.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
> index 561d46d860b7..0d4d358152d7 100644
> --- a/drivers/mtd/nand/raw/meson_nand.c
> +++ b/drivers/mtd/nand/raw/meson_nand.c
> @@ -510,7 +510,7 @@ static void meson_nfc_set_user_byte(struct nand_chip *nand, u8 *oob_buf)
>  	__le64 *info;
>  	int i, count;
>  
> -	for (i = 0, count = 0; i < nand->ecc.steps; i++, count += 2) {
> +	for (i = 0, count = 0; i < nand->ecc.steps; i++, count += (2 + nand->ecc.bytes)) {
>  		info = &meson_chip->info_buf[i];
>  		*info |= oob_buf[count];
>  		*info |= oob_buf[count + 1] << 8;
Seems something wrong with your logic here.
I think this code should most likely look like this:

for (i = 0, count = 0; i < nand->ecc.steps; i++, count += nand->ecc.bytes) {
    info = &meson_chip->info_buf[i];
    *info |= oob_buf[count];
    if (nand->ecc.bytes > 1)
      *info |= oob_buf[count + 1] << 8;
}


> @@ -523,7 +523,7 @@ static void meson_nfc_get_user_byte(struct nand_chip *nand, u8 *oob_buf)
>  	__le64 *info;
>  	int i, count;
>  
> -	for (i = 0, count = 0; i < nand->ecc.steps; i++, count += 2) {
> +	for (i = 0, count = 0; i < nand->ecc.steps; i++, count += (2 + nand->ecc.bytes)) {
>  		info = &meson_chip->info_buf[i];
>  		oob_buf[count] = *info;
>  		oob_buf[count + 1] = *info >> 8;
And there:

for (i = 0, count = 0; i < nand->ecc.steps; i++, count += nand->ecc.bytes) {
    info = &meson_chip->info_buf[i];
    oob_buf[count] = *info;
    if (nand->ecc.bytes > 1)
        oob_buf[count + 1] = *info >> 8;
}


This is more similar to the behavior of similar functions in the proprietary U-Boot.

--
Viacheslav Bocharov
Arseniy Krasnov Nov. 9, 2023, 9:09 a.m. UTC | #2
Hello, thanks for review!

On 09.11.2023 11:06, Viacheslav Bocharov wrote:
> Hi!
> 
> On Thu, 2023-11-09 at 08:39 +0300, Arseniy Krasnov wrote:
>> In case of MTD_OPS_AUTO_OOB mode, MTD/NAND layer fills/reads OOB buffer
>> according current OOB layout so we need to follow it in the driver.
>>
>> Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
>> ---
>>  drivers/mtd/nand/raw/meson_nand.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
>> index 561d46d860b7..0d4d358152d7 100644
>> --- a/drivers/mtd/nand/raw/meson_nand.c
>> +++ b/drivers/mtd/nand/raw/meson_nand.c
>> @@ -510,7 +510,7 @@ static void meson_nfc_set_user_byte(struct nand_chip *nand, u8 *oob_buf)
>>  	__le64 *info;
>>  	int i, count;
>>  
>> -	for (i = 0, count = 0; i < nand->ecc.steps; i++, count += 2) {
>> +	for (i = 0, count = 0; i < nand->ecc.steps; i++, count += (2 + nand->ecc.bytes)) {
>>  		info = &meson_chip->info_buf[i];
>>  		*info |= oob_buf[count];
>>  		*info |= oob_buf[count + 1] << 8;
> Seems something wrong with your logic here.
> I think this code should most likely look like this:
> 
> for (i = 0, count = 0; i < nand->ecc.steps; i++, count += nand->ecc.bytes) {
>     info = &meson_chip->info_buf[i];
>     *info |= oob_buf[count];
>     if (nand->ecc.bytes > 1)
>       *info |= oob_buf[count + 1] << 8;
> }

For 64 bytes OOB and 512 bytes ECC this driver reports free areas as:

AA AA BB BB BB BB BB BB BB BB BB BB BB BB BB BB
AA AA BB BB BB BB BB BB BB BB BB BB BB BB BB BB
AA AA BB BB BB BB BB BB BB BB BB BB BB BB BB BB
AA AA BB BB BB BB BB BB BB BB BB BB BB BB BB BB

where AA is free byte(user byte), BB - ECC codes. So to access user bytes
we need bytes 0,1,16,17,32,33,48,49. nand->ecc.bytes == 14, so 'count' is
increased at 16 every iteration, so i guess this is correct.

WDYT?

Thanks, Arseniy

> 
> 
>> @@ -523,7 +523,7 @@ static void meson_nfc_get_user_byte(struct nand_chip *nand, u8 *oob_buf)
>>  	__le64 *info;
>>  	int i, count;
>>  
>> -	for (i = 0, count = 0; i < nand->ecc.steps; i++, count += 2) {
>> +	for (i = 0, count = 0; i < nand->ecc.steps; i++, count += (2 + nand->ecc.bytes)) {
>>  		info = &meson_chip->info_buf[i];
>>  		oob_buf[count] = *info;
>>  		oob_buf[count + 1] = *info >> 8;
> And there:
> 
> for (i = 0, count = 0; i < nand->ecc.steps; i++, count += nand->ecc.bytes) {
>     info = &meson_chip->info_buf[i];
>     oob_buf[count] = *info;
>     if (nand->ecc.bytes > 1)
>         oob_buf[count + 1] = *info >> 8;
> }
> 
> 
> This is more similar to the behavior of similar functions in the proprietary U-Boot.
> 
> --
> Viacheslav Bocharov
>
Miquel Raynal Nov. 30, 2023, 10:36 a.m. UTC | #3
On Thu, 2023-11-09 at 05:39:53 UTC, Arseniy Krasnov wrote:
> In case of MTD_OPS_AUTO_OOB mode, MTD/NAND layer fills/reads OOB buffer
> according current OOB layout so we need to follow it in the driver.
> 
> Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>

Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git nand/next, thanks.

Miquel
diff mbox series

Patch

diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
index 561d46d860b7..0d4d358152d7 100644
--- a/drivers/mtd/nand/raw/meson_nand.c
+++ b/drivers/mtd/nand/raw/meson_nand.c
@@ -510,7 +510,7 @@  static void meson_nfc_set_user_byte(struct nand_chip *nand, u8 *oob_buf)
 	__le64 *info;
 	int i, count;
 
-	for (i = 0, count = 0; i < nand->ecc.steps; i++, count += 2) {
+	for (i = 0, count = 0; i < nand->ecc.steps; i++, count += (2 + nand->ecc.bytes)) {
 		info = &meson_chip->info_buf[i];
 		*info |= oob_buf[count];
 		*info |= oob_buf[count + 1] << 8;
@@ -523,7 +523,7 @@  static void meson_nfc_get_user_byte(struct nand_chip *nand, u8 *oob_buf)
 	__le64 *info;
 	int i, count;
 
-	for (i = 0, count = 0; i < nand->ecc.steps; i++, count += 2) {
+	for (i = 0, count = 0; i < nand->ecc.steps; i++, count += (2 + nand->ecc.bytes)) {
 		info = &meson_chip->info_buf[i];
 		oob_buf[count] = *info;
 		oob_buf[count + 1] = *info >> 8;