MLP Report

Errata and Contingencies
Operating System
Failing Test
Expiry Date
ID
Number
Type
Error Description
Windows 7
Windows 7 64-bit
Windows Vista
Windows Vista 64-bit
1) Class Driver AC3
Test - Win7
(System)
2) HDAudio Class
Driver Test - Vista
or Server08
(System)
06/01/2010
1256
Erratum
The HD Audio class driver hdaudio.sys exposes AC-
3 data ranges on S/PDIF Kernel Streaming pins
incorrectly.
The compressed AC-3 transport is "stereo", "16-
bit", and at the same sample rate as the
uncompressed format. As such, AC-3 data ranges
are expected to have MaximumChannels = 2, and
MinimumBitDepth = MaximumBitDepth = 16.
However, the HD Audio class driver sometimes
incorrectly exposes a MaximumBitDepth of 24 or
even 32.
Windows 7
Windows 7 64-bit
Window Vista
Windows Vista 64-bit
1) Class Driver
Fidelity Test - Win7
(System, Manual)
2) HDAudio Class
Driver Fidelity
Test-Vista (System,
Manual)
12/01/2010
1012
Erratum
Fidelity uses too small of a buffer and wakes up
too infrequently during the System Activity test.
This causes errors like: Noise level during system
activity on (left or right) channel 73.2016 dB: ***
FAIL *** (requirement >= 80 dB)
Windows 7
Windows 7 64-bit
Window Vista
Windows Vista 64-bit
1) Class Driver
Fidelity Test - Win7
(System, Manual)
2) HDAudio Class
Driver Fidelity
Test-Vista (System,
Manual)
07/31/2011
598
Erratum
The European Union requires the headphone
output level to be <= 150 mVrms for headphone
jacks. There's a note in WLP requirement AUDIO-
0006 that states, in the presence of regional
regulations, the output level requirement for
headphones is dropped from >= 1000 mVrms to
>= 120 mVrms. This provides freedom for
manufacturers to meet both the EU <= 150
mVrms @ 32 Ohms and the WLP >= 120 mVrms @
32 Ohms requirements. The Fidelity Test tests
headphones at 300 Ohm load, though. Without
knowledge of the output impedance at the jack,
the test cannot extrapolate what the output level
at 32 Ohms would have been from the output
level at 300 Ohms. The test assumes that the
output level at 32 Ohms will be *less* than the
output level at 300 Ohms, though. So any
measurement >= 120 mVrms at 300 Ohms "could
be" a passing result, depending on the output
impedance.
Windows 7
Windows 7 64-bit
Window Vista
Windows Vista 64-bit
1) Class Driver
Fidelity Test - Win7
(System, Manual)
2) HDAudio Class
Driver Fidelity
Test-Vista (System,
Manual)
3) Fidelity Test
(System, Manual)
08/09/2010
1801
Erratum
There is a test bug which causes the measurement
of system noise during Render Power Transition
Test to be about 3 dB worse than it should be. This
filter forgives errors up to 6 dB.