Hi Kenneth, hi Atharva,
Thanks for bringing the two threads together. I've tried your suggestion on my
iMac20,1 (1002:7340 / 106b:0218, revision 0x41), with SMU firmware 53.38.0. I
tried two warm boots and both failed.
On the same AMD staging base as my RFC, I moved UCLK enablement to the
beginning of navi10_set_default_dpm_table(), along with the readback check and
supported-feature update. I removed the later enable and refresh from
post-init. UCLK was still excluded from enable-all, and both memory-voltage
features stayed the same. I didn't add any delay or extra mailbox tracing.
Both boots reported:
SMU: No response msg_reg: 8 resp_reg: 0
in params:00000008
Apple 0218 default-table UCLK enable failed: -62
AMDGPU failed to bind in both cases. I checked that the experimental module was
loaded and the firmware files hadn't changed.
This also fits an earlier test with T2 7.1.8. With UCLK excluded from
enable-all, I tried enabling it separately immediately after
smu_v11_0_system_features_control(smu, true) returned successfully. The trace
shows EnableAllSmuFeatures returning 0x1, then EnableSmuFeaturesLow with
argument 0x8 timing out with response 0 and -ETIME.
The default-table function is reached only after enable-all returns
successfully, so waiting for that acknowledgement doesn't seem to be enough on
this board. I don't yet know whether it needs more time or some other
initialization step. I'd keep post-init for now: that version passed the ten
recorded AMD staging warm boots. These tests don't establish the earliest safe
point.
As for Apple, I can't speak for Apple or confirm their approval. I'm testing
this as a Linux user. Do we need their input before merging an Apple-specific
workaround? If so, could AMD help find the right contact? I'd still welcome a
fix for the underlying firmware problem.
I agree we should coordinate the two patches. Mine covers only 0218/rev 0x41;
Atharva's covers 0219. We'd need to test the combined change on both boards
before broadening the match.
Thanks!
Ed
