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Kernel: Read and report AC'97 codec revision

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This might help with debugging on bare metal. Since the minimum version
that can be specified is revision 2.1, and we do not use any feature
from revision 2.2 or newer, this is merely future-proofing ourselves
for new features yet to be built. Additionally, removing the `VERIFY()`
ensures we will not crash on cards that only support earlier revisions.
This commit is contained in:
Jelle Raaijmakers 2022-02-27 15:57:06 +01:00 • committed by Andreas Kling
parent 9a46573ffc
commit 694ff12272
2 changed files with 7 additions and 1 deletions
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6
Kernel/Devices/Audio/AC97.cpp
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@ -87,8 +87,12 @@ UNMAP_AFTER_INIT ErrorOr<void> AC97::initialize()
// Reset mixer
m_io_mixer_base.offset(NativeAudioMixerRegister::Reset).out<u16>(1);
// Read out AC'97 codec revision
auto extended_audio_id = m_io_mixer_base.offset(NativeAudioMixerRegister::ExtendedAudioID).in<u16>();
VERIFY((extended_audio_id & ExtendedAudioMask::Revision) >> 10 == AC97Revision::Revision23);
m_codec_revision = static_cast<AC97Revision>(((extended_audio_id & ExtendedAudioMask::Revision) >> 10) & 0b11);
dbgln_if(AC97_DEBUG, "AC97 @ {}: codec revision {:#02b}", pci_address(), to_underlying(m_codec_revision));
if (m_codec_revision == AC97Revision::Reserved)
return ENOTSUP;
// Enable variable and double rate PCM audio if supported
auto extended_audio_status_control_register = m_io_mixer_base.offset(NativeAudioMixerRegister::ExtendedAudioStatusControl);