Kernel/Audio: Propagate errors when creating AudioChannels

While doing this, we can also just return a normal RefPtr instead of a
LockRefPtr, because we create these channels when initializing an audio
controller, and never change the pointer in AudioController instances
after their initialization, hence no locking is necessary.

Kernel/Devices/Audio/AC97.cpp

@@ -88,7 +88,7 @@ UNMAP_AFTER_INIT ErrorOr<void> AC97::initialize(Badge<AudioManagement>)
     dbgln_if(AC97_DEBUG, "AC97 @ {}: mixer base: {:#04x}", device_identifier().address(), m_mixer_io_window);
     dbgln_if(AC97_DEBUG, "AC97 @ {}: bus base: {:#04x}", device_identifier().address(), m_bus_io_window);
 
-    m_audio_channel = AudioChannel::must_create(*this, 0);
+    m_audio_channel = TRY(AudioChannel::create(*this, 0));
 
     // Read out AC'97 codec revision and vendor
     auto extended_audio_id = m_mixer_io_window->read16(NativeAudioMixerRegister::ExtendedAudioID);
@@ -177,7 +177,7 @@ void AC97::set_pcm_output_volume(u8 left_channel, u8 right_channel, Muted mute)
     m_mixer_io_window->write16(NativeAudioMixerRegister::SetPCMOutputVolume, volume_value);
 }
 
-LockRefPtr<AudioChannel> AC97::audio_channel(u32 index) const
+RefPtr<AudioChannel> AC97::audio_channel(u32 index) const
 {
     if (index == 0)
         return m_audio_channel;

Kernel/Devices/Audio/AC97.h

@@ -7,6 +7,7 @@
 #pragma once
 
 #include <AK/Error.h>
+#include <AK/RefPtr.h>
 #include <Kernel/Bus/PCI/API.h>
 #include <Kernel/Bus/PCI/Device.h>
 #include <Kernel/Devices/Audio/Controller.h>
@@ -167,7 +168,7 @@ private:
 
     // ^AudioController
     virtual ErrorOr<void> initialize(Badge<AudioManagement>) override;
-    virtual LockRefPtr<AudioChannel> audio_channel(u32 index) const override;
+    virtual RefPtr<AudioChannel> audio_channel(u32 index) const override;
     virtual ErrorOr<size_t> write(size_t channel_index, UserOrKernelBuffer const& data, size_t length) override;
     virtual ErrorOr<void> set_pcm_output_sample_rate(size_t channel_index, u32 samples_per_second_rate) override;
     virtual ErrorOr<u32> get_pcm_output_sample_rate(size_t channel_index) override;
@@ -185,7 +186,7 @@ private:
     NonnullOwnPtr<AC97Channel> m_pcm_out_channel;
     u32 m_sample_rate { 0 };
     bool m_variable_rate_pcm_supported { false };
-    LockRefPtr<AudioChannel> m_audio_channel;
+    RefPtr<AudioChannel> m_audio_channel;
 };
 
 }

Kernel/Devices/Audio/Channel.cpp

@@ -13,12 +13,9 @@
 
 namespace Kernel {
 
-UNMAP_AFTER_INIT NonnullLockRefPtr<AudioChannel> AudioChannel::must_create(AudioController const& controller, size_t channel_index)
+UNMAP_AFTER_INIT ErrorOr<NonnullRefPtr<AudioChannel>> AudioChannel::create(AudioController const& controller, size_t channel_index)
 {
-    auto audio_device_or_error = DeviceManagement::try_create_device<AudioChannel>(controller, channel_index);
-    // FIXME: Find a way to propagate errors
-    VERIFY(!audio_device_or_error.is_error());
-    return audio_device_or_error.release_value();
+    return *TRY(DeviceManagement::try_create_device<AudioChannel>(controller, channel_index));
 }
 
 AudioChannel::AudioChannel(AudioController const& controller, size_t channel_index)

Kernel/Devices/Audio/Channel.h

@@ -20,7 +20,7 @@ class AudioChannel final
     friend class DeviceManagement;
 
 public:
-    static NonnullLockRefPtr<AudioChannel> must_create(AudioController const&, size_t channel_index);
+    static ErrorOr<NonnullRefPtr<AudioChannel>> create(AudioController const&, size_t channel_index);
     virtual ~AudioChannel() override = default;
 
     // ^CharacterDevice

Kernel/Devices/Audio/Controller.h

@@ -8,11 +8,11 @@
 
 #include <AK/IntrusiveList.h>
 #include <AK/OwnPtr.h>
+#include <AK/RefPtr.h>
 #include <Kernel/Bus/PCI/Access.h>
 #include <Kernel/Bus/PCI/Device.h>
 #include <Kernel/Devices/Audio/Channel.h>
 #include <Kernel/Devices/Device.h>
-#include <Kernel/Library/LockRefPtr.h>
 #include <Kernel/Library/LockWeakable.h>
 #include <Kernel/Locking/Mutex.h>
 #include <Kernel/Memory/PhysicalPage.h>
@@ -30,7 +30,7 @@ class AudioController
 public:
     virtual ~AudioController() = default;
 
-    virtual LockRefPtr<AudioChannel> audio_channel(u32 index) const = 0;
+    virtual RefPtr<AudioChannel> audio_channel(u32 index) const = 0;
     virtual ErrorOr<size_t> write(size_t channel_index, UserOrKernelBuffer const& data, size_t length) = 0;
 
     virtual ErrorOr<void> initialize(Badge<AudioManagement>) = 0;

Kernel/Devices/Audio/IntelHDA/Controller.cpp

@@ -92,7 +92,7 @@ UNMAP_AFTER_INIT ErrorOr<void> Controller::initialize(Badge<AudioManagement>)
         return result.release_error();
     }
 
-    m_audio_channel = AudioChannel::must_create(*this, fixed_audio_channel_index);
+    m_audio_channel = TRY(AudioChannel::create(*this, fixed_audio_channel_index));
     return {};
 }
 
@@ -290,7 +290,7 @@ ErrorOr<void> Controller::reset()
     return {};
 }
 
-LockRefPtr<AudioChannel> Controller::audio_channel(u32 index) const
+RefPtr<AudioChannel> Controller::audio_channel(u32 index) const
 {
     if (index != fixed_audio_channel_index)
         return {};

Kernel/Devices/Audio/IntelHDA/Controller.h

@@ -9,6 +9,7 @@
 #include <AK/Error.h>
 #include <AK/NonnullOwnPtr.h>
 #include <AK/NonnullRefPtr.h>
+#include <AK/RefPtr.h>
 #include <AK/Vector.h>
 #include <Kernel/Bus/PCI/Device.h>
 #include <Kernel/Devices/Audio/Channel.h>
@@ -16,7 +17,6 @@
 #include <Kernel/Devices/Audio/IntelHDA/OutputPath.h>
 #include <Kernel/Devices/Audio/IntelHDA/RingBuffer.h>
 #include <Kernel/IOWindow.h>
-#include <Kernel/Library/LockRefPtr.h>
 
 namespace Kernel::Audio::IntelHDA {
 
@@ -65,7 +65,7 @@ private:
     ErrorOr<void> reset();
 
     // ^AudioController
-    virtual LockRefPtr<AudioChannel> audio_channel(u32 index) const override;
+    virtual RefPtr<AudioChannel> audio_channel(u32 index) const override;
     virtual ErrorOr<size_t> write(size_t channel_index, UserOrKernelBuffer const& data, size_t length) override;
     virtual ErrorOr<void> initialize(Badge<AudioManagement>) override;
     virtual ErrorOr<void> set_pcm_output_sample_rate(size_t channel_index, u32 samples_per_second_rate) override;
@@ -79,7 +79,7 @@ private:
     OwnPtr<ResponseInboundRingBuffer> m_response_buffer;
     Vector<NonnullRefPtr<Codec>> m_codecs {};
     OwnPtr<OutputPath> m_output_path;
-    LockRefPtr<AudioChannel> m_audio_channel;
+    RefPtr<AudioChannel> m_audio_channel;
 };
 
 }

Kernel/Devices/Audio/Management.h

@@ -9,10 +9,10 @@
 #include <AK/Badge.h>
 #include <AK/Error.h>
 #include <AK/IntrusiveList.h>
+#include <AK/NonnullRefPtr.h>
 #include <AK/OwnPtr.h>
 #include <AK/Types.h>
 #include <Kernel/Devices/Audio/Controller.h>
-#include <Kernel/Library/LockRefPtr.h>
 
 namespace Kernel {