Dear Lukasz Majewski,
In message 1399552067-31208-1-git-send-email-l.majewski@samsung.com you wrote:
Up till now the CRC32 of received data was calculated unconditionally. The standard crc32 implementation causes long delay when large images were uploaded.
The "dfu_hash_algo" environment variable gives the opportunity to enable on demand (when e.g. debugging) the hash (crc32) calculation. It can be done without need to recompile the u-boot binary and reuses the generic hash framework.
By default the crc32 is NOT calculated anymore.
I consider this a VARY BAD idea, as it causes a significant decrease of reliability and robustness of the systems. Please do not do this.
In any case, if you introduce this, the behaviour should be documented, and the default setting should be such as to keep the previous behaviour, i. e. CRC checking should remain on by default. then people who are willing to trade reliability for a little speed can still switch it off, but the unawarerest of the users will not suffer.
Best regards,
Wolfgang Denk