intel-hda: valid registers are unknown
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
QEMU |
Expired
|
Undecided
|
Unassigned |
Bug Description
According to HDA specification, "3.1.2 General Register Behaviors and Access Requirements":
"All controller registers must be addressable as byte, Word, and Dword quantities."
But e.g. if you try the following to reset and enable the CORB, assuming es:esi contains the base MMIO address of the controller,
es or [esi+4bh], byte 80h ; reset CORB
corbresetloop:
es test [esi+4bh], byte 80h ; is HW done resetting yet?
jnz corbreset1ok ; yes, bit is now 1
hlt ; wait a little bit
jmp corbresetloop ; and check again
corbreset1ok:
es and [esi+4bh], byte 7fh ; clear the bit
It will hang indefinitely because the bit never gets set, and if you enable debug output of the controller with "-device intel-hda,debug=1", you will see infinitely the line "unknown register, addr 0x4b" output. The same code on a real hardware (I tried with ICH7M) works fine, as it should according to the spec.
Host/guest/version does not matter (I am writing own drivers) --- as of right now, latest version still has this code:
https:/
which seems to emit "unknown register" message in intel_hda_
The QEMU project is currently moving its bug tracking to another system.
For this we need to know which bugs are still valid and which could be
closed already. Thus we are setting the bug state to "Incomplete" now.
If the bug has already been fixed in the latest upstream version of QEMU,
then please close this ticket as "Fix released".
If it is not fixed yet and you think that this bug report here is still
valid, then you have two options:
1) If you already have an account on gitlab.com, please open a new ticket
for this problem in our new tracker here:
https:/ /gitlab. com/qemu- project/ qemu/-/ issues
and then close this ticket here on Launchpad (or let it expire auto-
matically after 60 days). Please mention the URL of this bug ticket on
Launchpad in the new ticket on GitLab.
2) If you don't have an account on gitlab.com and don't intend to get
one, but still would like to keep this ticket opened, then please switch
the state back to "New" or "Confirmed" within the next 60 days (other-
wise it will get closed as "Expired"). We will then eventually migrate
the ticket automatically to the new system (but you won't be the reporter
of the bug in the new system and thus you won't get notified on changes
anymore).
Thank you and sorry for the inconvenience.