Re: strange ld(4) behavior when reading off end of disk

[Michael van Elst <mlelstv%serpens.de@localhost>]

On Thu, Sep 10, 2020 at 08:30:56PM -0400, Greg Troxel wrote:
> 
> Are you saying this is a bug in my particular uSD card,

The Linux code suggests that it is all of it.

It falls back to single I/O for

- buggy cards (mostly old cards used in SPI mode)
- buggy controllers (with a quirk)
- when doing "reliable writes"
- after a read error (to identify the exact error position on retry)

However, it also uses MMC_SET_BLOCK_COUNT ("CMD23") when available.
This is a counter for MMC cards that limits a multi-read/write command
and that probably avoids the issue.