On 2019-08-24 15:51, Cezary Rojewski wrote:
On 2019-08-23 23:39, Mark Brown wrote:
On Fri, Aug 23, 2019 at 03:12:18PM -0500, Pierre-Louis Bossart wrote:
On 8/23/19 1:44 PM, Cezary Rojewski wrote:
Wasn't lying about FW version being unreliable. Let's say vendor
receives quick FW drop with new RCR.. such eng drop may carry invalid
numbers such as 0.0.0.0..
In general, I try to avoid relying on FW version whenever possible. It
can be dumped for debug reasons, true, but to be relied on? Not really.
Goodness, that's really bad. I didn't realize this.
At a previous employer I modified our build stamping
infrastructure to also include both a timestamp and a serialized
build number in the version number since one of my colleagues was
fond of sending people prereleases of what he was working on to
other people with identical version numbers on different
binaries leading to much confusion and checksumming. You do see
a lot of things with those serialized version numbers, especially
SVN based projects.
Personally, I'm against all hardcodes and would simply recommend all
user to redirect their symlinks when they do switch kernel - along with
dumping warning/ error message in dmesg. Hardcodes bring problems with
forward compatibility and that's why host should offload them away to
FW.
Cezary, I know you are not responsible for all this, but at this
point if we
(Intel) can't guarantee any sort of interoperability with both
firmware and
topology we should make it clear that this driver is not recommended
unless
specific versions of the firmware/topology are used, and as a
consequence
the typical client distros and desktop/laptop users should use HDaudio
legacy or SOF (for DMICs)
Not the most elegent solution but I'm wondering if keeping a copy
of the driver as is around and using new locations for the fixed
firmware might be the safest way to handle this. We could have a
wrapper which tries to load the newer firmware and uses the fixed
driver code if that's there, otherwise tries the old driver with
the existing firmware paths. This is obviously a horror show and
leaves the old code sitting there but given the mistakes that
have been made the whole situation looks like a house of cards.
Thanks for the feedback Mark. While I'm not yet on the "SOF will fix
this" train, I'm keen to agree to leaving this entirely to SOF if it
comes down to us duplicating /skylake.
However, we are not going to give up that easily. I'll see if some
"golden config" hardcodes can't be provided in some legacy.c file which
would be fetched if initial setup fails. E.g.: 2cores, 3ssps, 1PAGE_SIZE
per trace buffer.. and such. There are quite a few factors to take into
consideration though. If "asking" user via dmesg to upgrade the firmware
if his/her setup contains obsolete binary is really not an option, then
some magic words got to be involved.
Czarek
On the second thought what if instead of duplicating kernel code,
binaries would be duplicated?
I.e. rather than targeting /intel/dsp_fw_cnl.bin, _new_ /skylake would
be expecting /intel/dsp_fw_cnl_release.bin? Same with topology binaries.
In such case, we "only" need to figure out how to propagate new files to
Linux distos so whenever someone updates their kernel, new binaries are
already present in their /lib/firmware.
If such option is valid, we can postpone /skylake upgrade till 5.4
merging window closes and the patches (rough estimation is 150) would
descend upon alsa-devel in time between 5.4 and 5.5.
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