On Tue, Oct 4, 2016 at 5:12 PM, Linus Torvalds
[off-list ref] wrote:

On Tue, Oct 4, 2016 at 5:00 PM, Luis R. Rodriguez [off-list ref] wrote:

quoted

I am not sure how/why a firmware loading daemon would be a better
idea now. What Marc describes that Josh proposed with signals for
userspcae seems more aligned with what we likely need

Quite frankly, I doubt you want a signal.

You will want to have some way to specify where the firmware files
are. Right now we have "fw_path[]" which is hardcoded except for the
first entry that can be set as a module parameter. But you'd probably
want to expand on that, which implies some /sys or /proc interface.

And once you do that, wouldn't it make more sense to just make the
"update the firmware path /proc/sys/kernel/fw_path file" make things
re-search for firmware?

We can, but re-searching for firmware assumes we cache pending
firmware, we currently don't, we just either process sync or async
firmware requests.

In other words, the interface has to be something *sensible*. Not some
idiotic ad-hoc "send a signal" (of which that stupid original patch
was just a very odd example).

Note that the races are beyond firmware, so all
kernel_read_file_from_path() users, as such re-using such old /sys/
interafeces for firmware will not suffice to cover all ground now for
the same race for other possible users.

 Luis