[PATCH] fpga zynq: Check the bitstream for validity
flat view
STALE3625d
From: Jason Gunthorpe <hidden>
Date: 2016-10-28 16:55:55
On Fri, Oct 28, 2016 at 06:36:06PM +0200, Matthias Brugger wrote:
Sure but we are checking here that the bitstream passed to the kernel is correct.
The intent to check if it *possible* that the bitstream is correct. Correct means that DONE will assert after programming. A 4 byte bitstream will never assert DONE. Arguably the threshold should be larger but we don't know what the true minimum is.
quoted hunk ↗ jump to hunk
+ /* All valid bitstreams are multiples of 32 bits */ + if (!count || (count % 4) != 0) + return -EINVAL; +
Too clever for my taste. Aside from this, is the general idea even OK? In my world I cannonize the bitstream to start with the sync word, but others may not be doing that. I designed this patch based on the prior work to remove the auto-detection, eg that the driver should be passed a canonized bitstream. The problem with the way it is now is how hard it is to figure out what the right bitstream format should be. Clear instructions to canonize by droping the header before the sync word and byteswap so the sync word is in the given order is much clearer.. Jason