On 08/10/15 15:45, Animesh Manna wrote:
On 10/8/2015 5:53 PM, Mika Kuoppala wrote:
Animesh Manna <animesh.manna@xxxxxxxxx> writes:
On 9/21/2015 2:00 PM, Mika Kuoppala wrote:
Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> writes:
On Fri, 18 Sep 2015, Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
wrote:
If csr/dmc firmware is known to be outdated, notify
user.
What would break if we requested a firmware version that works? Or
we've
made it so that we only request the major version because there's not
supposed to be changes like this between minor versions...?
I guess the question is more of a what should we do
if there is only outdated (known bad) firmware available.
Refuse to load and limb onwards, or return with error code
on driver init.
Latter would force firmware and version to be mandatory and the
version to be tightly coupled to kernel driver version.
A softlink is used to use recommended firmware for dmc and the same
information is published through 01.org for the firmware user.
Imo, we should not have this kind of hack in code which will change
over time and this is responsibility of repo-owner to link correct
recommended firmware for new kernel update.
On machines that had 1.19 symlinked, in filesystem, execlist submission
sometimes broke due to interrupt delivery problem. To reach a conclusion
that it was csr firmware, before 1.21 was out, took quite amount of work.
I bet there are still machines with 1.19 only, and we get to
wade through error states trying to connect the dots.
The dmc/csr firmware is part of our driver functionality. Apparently
it is very tightly coupled to our driver functionality as it can
break things outside of its own domain.
And currently it is loosely coupled black box with our driver,
through symlink, accepting any version that happens to be in customers
filesystem.
So we recommend latest in website and end up in a situation
that user gets what happens to be in filesystem. Even a known
broken version? And we will keep debugging these problems caused by
broken version? I don't want any more dimensions in our triaging
space, the distributio/firmware version dimension.
Symlink also means that bisectability is very close to worthless on these
kind of bugs. Both in our machines and also on customers. We have
loosely coupled, black box entity, affecting our driver depending
on customers filesystem. Symlink threw that valuable tool out, and
we gained what?
So we are left with triaging. Which is true detective work as there are
no traces of firmware versions nor loading success/fails on
logs/error states.
From where I look at, the version blacklist is not a hack. It is a cure.
I completely understand your concern and we discussed a lot on same
during firmware naming
convention and finally decided to have symlink.
If we really want to tightly couple firmware and driver then imo putting
exact firmware name
will be better option.
Next I saw your subsequent patch where you are not loading the firmware
if it is older than 1.21.
http://lists.freedesktop.org/archives/intel-gfx/2015-September/076422.html
Curious to know the gpu-hang issue present for any version less than 1.21.
-Animesh
The GuC loader always had this sort of functionality, so the driver can
be built to know that anything older than a specific minor version is bogus.
The proposed unified loader therefore tested (=major, >=minor) criteria
for each of the various chunks of uC device firmware being loaded.
.Dave.
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
http://lists.freedesktop.org/mailman/listinfo/intel-gfx
