Re: [PATCH v2 1/2] mtd: spi-nor: sst: Fix write enable before AAI sequence

[Sanjaikumar V S <sanjaikumarvs@gmail.com>]

Hi Michael,

Thank you for the review.

> Raises concern about writes ending at odd offsets potentially having the same issue

The odd end address case (trailing byte) is already handled in the existing code at lines 243-255:

/* Write out trailing byte if it exists. */
if (actual != len) {
    ret = spi_nor_write_enable(nor);
    ...
    ret = sst_nor_write_data(nor, to, 1, buf + actual);
}

So write_enable is already called before writing the trailing byte. My patch only addresses the odd start case where BP clears WEL before the AAI sequence begins.

> Suggests simplifying the conditional logic by removing the length check

The condition `if (actual < len - 1)` avoids an unnecessary write_enable when len == 1 (single byte write at odd address, no AAI follows). But if you prefer unconditional write_enable for simplicity, I can change it in v3.

> Notes the patch lacks runtime testing

I don't have the hardware setup to test odd-address writes at the moment. The fix is based on code analysis. I have tested patch 2/2 (dirmap fallback) on hardware.

Please let me know if you'd like me to send a v3 with the simplified unconditional write_enable.

Thanks,
Sanjaikumar

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