tree 5c28b718ecdfc3e64d6280ece51f5271e4aadd22
parent 260de10f46c550aed2986bd92cabe7b2fdee1f33
author Rafał Miłecki <rafal@milecki.pl> 1702469634 +0100
committer Tom Rini <trini@konsulko.com> 1704487307 -0500

fw_env: keep calling read() until whole flash block is read

It's totally valid for read() to provide less bytes than requested
maximum. It may happen if there is no more data available yet or source
pushes data in small chunks.

This actually happens when trying to read env data from NVMEM device.
Kernel may provide NVMEM content in page size parts (like 4096 B).

This fixes warnings like:
Warning on /sys/bus/nvmem/devices/u-boot-env0/nvmem: Attempted to read 16384 bytes but got 4096
Warning on /sys/bus/nvmem/devices/u-boot-env0/nvmem: Attempted to read 12288 bytes but got 4096
Warning on /sys/bus/nvmem/devices/u-boot-env0/nvmem: Attempted to read 8192 bytes but got 4096

Since the main loop in flash_read_buf() is used to read blocks this
patch adds a new nested one.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>