[PATCH v2] sf: Querying write-protect status before operating the flash

[Tudor.Ambarus at microchip.com]

Hi,

+ Michael

On 11/15/21 4:37 AM, chaochao2021666 at 163.com wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> From: chao zeng <chao.zeng at siemens.com>
> 
> When operating the write-protection flash,spi_flash_std_write() and
> spi_flash_std_erase() would return wrong result.The flash is protected,
> but write or erase the flash would show "OK".
> 
> Check the flash write protection state before operating the flash
> and give a prompt to show it has been locked if the write-protection
> has enbale
> 
> Signed-off-by: chao zeng <chao.zeng at siemens.com>
> 
> ---
> 
> Changes for V2:
>      - Return 0 not ENOPROTOOPT to refelect the flash feature
>      - Output prompt information
> ---
>  drivers/mtd/spi/sf_probe.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/mtd/spi/sf_probe.c b/drivers/mtd/spi/sf_probe.c
> index f461082e03..995801817d 100644
> --- a/drivers/mtd/spi/sf_probe.c
> +++ b/drivers/mtd/spi/sf_probe.c
> @@ -109,6 +109,11 @@ static int spi_flash_std_write(struct udevice *dev, u32 offset, size_t len,
>         struct mtd_info *mtd = &flash->mtd;
>         size_t retlen;
> 
> +       if (flash->flash_is_locked && flash->flash_is_locked(flash, offset, len)) {
> +               printf("SF: Flash is locked\n");

I would use a debug message, it's a flash specific thing. Also, I would update
a bit the message, something like
"SF: Flash has protected areas in the requested length. Writes will be ignored on those."

> +               return 0;

Michael has suggested to drop this line. I agree with him, check the conversation
on the previous email thread.

Cheers,
ta

> +       }
> +
>         return mtd->_write(mtd, offset, len, &retlen, buf);
>  }
> 
> @@ -127,6 +132,11 @@ static int spi_flash_std_erase(struct udevice *dev, u32 offset, size_t len)
>         instr.addr = offset;
>         instr.len = len;
> 
> +       if (flash->flash_is_locked && flash->flash_is_locked(flash, offset, len)) {
> +               printf("SF: Flash is locked\n");
> +               return 0;
> +       }
> +
>         return mtd->_erase(mtd, &instr);
>  }
> 
> --
> 2.33.1
> 
>