sound/core/pcm_trace.h
Source file repositories/reference/linux-study-clean/sound/core/pcm_trace.h
File Facts
- System
- Linux kernel
- Corpus path
sound/core/pcm_trace.h- Extension
.h- Size
- 5090 bytes
- Lines
- 150
- Domain
- Driver Families
- Bucket
- sound/core
- Inferred role
- Driver Families: implementation source
- Status
- source implementation candidate
Why This File Exists
Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/tracepoint.htrace/define_trace.h
Detected Declarations
- No top-level syscall, struct, function, initcall, or export declaration detected by the generator.
Annotated Snippet
#undef TRACE_SYSTEM
#define TRACE_SYSTEM snd_pcm
#define TRACE_INCLUDE_FILE pcm_trace
#if !defined(_PCM_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
#define _PCM_TRACE_H
#include <linux/tracepoint.h>
TRACE_EVENT(hwptr,
TP_PROTO(struct snd_pcm_substream *substream, snd_pcm_uframes_t pos, bool irq),
TP_ARGS(substream, pos, irq),
TP_STRUCT__entry(
__field( bool, in_interrupt )
__field( unsigned int, card )
__field( unsigned int, device )
__field( unsigned int, number )
__field( unsigned int, stream )
__field( snd_pcm_uframes_t, pos )
__field( snd_pcm_uframes_t, period_size )
__field( snd_pcm_uframes_t, buffer_size )
__field( snd_pcm_uframes_t, old_hw_ptr )
__field( snd_pcm_uframes_t, hw_ptr_base )
),
TP_fast_assign(
__entry->in_interrupt = (irq);
__entry->card = (substream)->pcm->card->number;
__entry->device = (substream)->pcm->device;
__entry->number = (substream)->number;
__entry->stream = (substream)->stream;
__entry->pos = (pos);
__entry->period_size = (substream)->runtime->period_size;
__entry->buffer_size = (substream)->runtime->buffer_size;
__entry->old_hw_ptr = (substream)->runtime->status->hw_ptr;
__entry->hw_ptr_base = (substream)->runtime->hw_ptr_base;
),
TP_printk("pcmC%dD%d%s/sub%d: %s: pos=%lu, old=%lu, base=%lu, period=%lu, buf=%lu",
__entry->card, __entry->device,
__entry->stream == SNDRV_PCM_STREAM_PLAYBACK ? "p" : "c",
__entry->number,
__entry->in_interrupt ? "IRQ" : "POS",
(unsigned long)__entry->pos,
(unsigned long)__entry->old_hw_ptr,
(unsigned long)__entry->hw_ptr_base,
(unsigned long)__entry->period_size,
(unsigned long)__entry->buffer_size)
);
TRACE_EVENT(xrun,
TP_PROTO(struct snd_pcm_substream *substream),
TP_ARGS(substream),
TP_STRUCT__entry(
__field( unsigned int, card )
__field( unsigned int, device )
__field( unsigned int, number )
__field( unsigned int, stream )
__field( snd_pcm_uframes_t, period_size )
__field( snd_pcm_uframes_t, buffer_size )
__field( snd_pcm_uframes_t, old_hw_ptr )
__field( snd_pcm_uframes_t, hw_ptr_base )
),
TP_fast_assign(
__entry->card = (substream)->pcm->card->number;
__entry->device = (substream)->pcm->device;
__entry->number = (substream)->number;
__entry->stream = (substream)->stream;
__entry->period_size = (substream)->runtime->period_size;
__entry->buffer_size = (substream)->runtime->buffer_size;
__entry->old_hw_ptr = (substream)->runtime->status->hw_ptr;
__entry->hw_ptr_base = (substream)->runtime->hw_ptr_base;
),
TP_printk("pcmC%dD%d%s/sub%d: XRUN: old=%lu, base=%lu, period=%lu, buf=%lu",
__entry->card, __entry->device,
__entry->stream == SNDRV_PCM_STREAM_PLAYBACK ? "p" : "c",
__entry->number,
(unsigned long)__entry->old_hw_ptr,
(unsigned long)__entry->hw_ptr_base,
(unsigned long)__entry->period_size,
(unsigned long)__entry->buffer_size)
);
TRACE_EVENT(hw_ptr_error,
TP_PROTO(struct snd_pcm_substream *substream, const char *why),
TP_ARGS(substream, why),
TP_STRUCT__entry(
__field( unsigned int, card )
__field( unsigned int, device )
__field( unsigned int, number )
__field( unsigned int, stream )
__string( reason, why )
Annotation
- Immediate include surface: `linux/tracepoint.h`, `trace/define_trace.h`.
- Atlas domain: Driver Families / sound/core.
- Implementation status: source implementation candidate.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.