Correct calculation of the erase sector size

[LemonBoy]

According to the documentation (page 95) you should add one to the value extracted from the CSD to obtain the real erase sector size.

[deepikabhavnani]

@LemonBoy - Thanks for the PR. Sector size should be incremented by 1. But seems erase size is still incorrect for the CSD Version 1 cards.

Erase size should be _erase_size =(BLOCK_SIZE_HC * (ext_bits(csd, 45, 39) + 1)). For explanation please refer to SD card specification Pg 94/95
SECTOR_SIZE - Value of 127 means 128 write blocks.

We do not have CSD version 1 card, Can you please update and verify.

[LemonBoy]

Alright, I've been fooled by the use of the byte offsets.
I think that's why the erase+program sequence ends up trashing the whole filesystem, there should be a way to ask the FS driver not to do so when the single-block erase isn't supported.

I've updated the PR, the ball's back into the FATFilesystem court.

[deepikabhavnani]

LG 👍