M5Stack CoreS3: CONFIG_FATFS_LONG_FILENAMES macro is not defined (BSP-786)

[AmedeeBulle]

The M5Stack CoreS3 BSP has the following test:

esp-bsp/bsp/m5stack_core_s3/m5stack_core_s3.c

Line 306 in 1bd663b

#if !CONFIG_FATFS_LONG_FILENAMES

The CONFIG_FATFS_LONG_FILENAMES macro doesn't exists as such, it is a header for the CONFIG_FATFS_LFN_xxx macros (reference)

I believe the correct way to test would be:

#ifdef CONFIG_FATFS_LFN_NONE

(This doesn't affect the working of the code as it just used to log a warning)

[github-actions]

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You are correct that CONFIG_FATFS_LONG_FILENAMES is a choice Kconfig symbol which selects one of the CONFIG_FATFS_LFN_* options, and that the actual options are:

• CONFIG_FATFS_LFN_NONE
• CONFIG_FATFS_LFN_HEAP
• CONFIG_FATFS_LFN_STACK [FATFS LFN (esp32); FATFS LFN (esp32s3)]

The documentation shows CONFIG_FATFS_LONG_FILENAMES as the menu entry “Long filename support”, under which those three concrete options live; the actual preprocessor symbols that get defined are the CONFIG_FATFS_LFN_* ones, not CONFIG_FATFS_LONG_FILENAMES itself. [FATFS LFN (esp32)]

So, using #ifdef CONFIG_FATFS_LONG_FILENAMES in the BSP is not aligned with how the Kconfig options are defined. A more correct check would be to test for the “no LFN” case explicitly, for example:

#ifdef CONFIG_FATFS_LFN_NONE
    // no long filename support
#else
    // long filename support enabled (heap or stack)
#endif

This matches the documented options and will behave consistently across ESP32 variants that expose the same CONFIG_FATFS_LONG_FILENAMES choice and its CONFIG_FATFS_LFN_* entries. [FATFS LFN (esp32); FATFS LFN (esp32s3)]

You can post back to the GitHub issue that:

• CONFIG_FATFS_LONG_FILENAMES is a Kconfig choice, not a C macro that is guaranteed to be defined.
• The BSP should instead check one of the concrete options, e.g. CONFIG_FATFS_LFN_NONE (or equivalently check for CONFIG_FATFS_LFN_HEAP / CONFIG_FATFS_LFN_STACK if it specifically wants “LFN enabled”).

[AmedeeBulle]

I just realized the same test is done for other BSPs, the issue is not limited to the M5Stack CoreS3

[espzav]

Hi @AmedeeBulle, thank you for report this issue. It seems that was changed in IDF6 - we will fix it. BSPs are backward compatible with IDF5, we will change it to this:

#if !defined(CONFIG_FATFS_LONG_FILENAMES) || defined(CONFIG_FATFS_LFN_NONE)

[mbwilliamson1581]

I propose the correct logic for the compiler macro is:

#if !(defined(CONFIG_FATFS_LONG_FILENAMES) || defined(CONFIG_FATFS_LFN_STACK) || defined(CONFIG_FATFS_LFN_HEAP))

This compiles correctly with 5.5.3