Hi Lucas,
Linux in particular does reinitialize this state and I expect any reasonable OS to do so.
Then what is the point of enabling it on U-Boot? Does it fix some issue whereby some mis-aligned piece of data cannot be properly aligned?
Yes, it fixes U-Boot USB on Tegra, when built with a recent toolchain. Fixing the alignment of some of the structures in the USB code should also be done, but this is a whole lot more invasive and requires some more thought, as the discussion about this on LKML shows. The issue doesn't show for older toolchains, as they by default emit code to work around unaligned accesses.
This patch fixes all unaligned issues, that may appear with recent toolchains. We avoid having to instruct the toolchain to work around unaligned accesses and gain better performance in cases where it is needed.
I am not too happy with enabling a lax behavior only to avoid an issue which apparently is diagnosed and could / should be fixed at its root. Can you point me to the relevant LKML thread so that I get the details and understand what prevents fixing this by 'simply' aligning the USB structures?
Thanks, Lucas
Amicalement,