eMMC stuck in 4k sector mode
Posted: July 24th, 2022, 19:30
I wanted to try if using 4k sectore size instead of 512B emulated sectors makes any difference in terms of performance on my 008GB0 eMMC disk, so I set USE_NATIVE_SECTOR in EXT_CSD to 1.
The performance difference turned out to be negligible, but 4k sectors are problematic e.g. because they are not supported by U-Boot loader.
Hence I would like to return to use emulated 512B sectors (the factory state of the disk).
However, writing 0 to USE_NATIVE_SECTOR[62] register has no effect.
As newer versions of the eMMC specification are not (yet) public, I'd like to know if this register happens to be write-once -- if so, we should document that in mmc-utils to prevent other people doing stupid mistakes like me now...
Anyone?
The performance difference turned out to be negligible, but 4k sectors are problematic e.g. because they are not supported by U-Boot loader.
Hence I would like to return to use emulated 512B sectors (the factory state of the disk).
However, writing 0 to USE_NATIVE_SECTOR[62] register has no effect.
As newer versions of the eMMC specification are not (yet) public, I'd like to know if this register happens to be write-once -- if so, we should document that in mmc-utils to prevent other people doing stupid mistakes like me now...
Anyone?