[Bug 1904490] Re: intel-hda: valid registers are unknown

[Launchpad Bug Tracker]

[Expired for QEMU because there has been no activity for 60 days.]

** Changed in: qemu
       Status: Incomplete => Expired

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https://bugs.launchpad.net/bugs/1904490

Title:
  intel-hda: valid registers are unknown

Status in QEMU:
  Expired

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://github.com/qemu/qemu/blob/master/hw/audio/intel-hda.c

  which seems to emit "unknown register" message in
  intel_hda_reg_find(), and this function does not take into account
  range of addresses that each register occupies.

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