ALSA: compress_offload: Add 64-bit safe timestamp infrastructure

The copied_total field in struct snd_compr_tstamp is a 32-bit value that can overflow on long-running high-bitrate streams, leading to incorrect calculations for buffer availablility. This patch adds a 64-bit safe timestamping mechanism. A new UAPI struct, snd_compr_tstamp64, is added which uses 64-bit types for byte counters. The relevant ops structures across the ASoC and core compress code are updated to use this new struct. ASoC drivers are updated to use u64 counters. Internal timestamps being u64 now, a compatibility function is added to convert the 64-bit timestamp back to the 32-bit format for legacy ioctl callers.

Joris Verhaegen committed 1 year ago

Commit 2c92e2f1 parent cbd676824 files · +125 −72Browse files

Showing the changes to include (4 of 24 files). Show all

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4 files

include/sound/compress_driver.h +1 −1
include/sound/soc-component.h +2 −2
include/sound/soc-dai.h +4 −3
include/uapi/sound/compress_offload.h +19 −0

include/sound/compress_driver.h+1−1

@@ -161,7 +161,7 @@ struct snd_compr_ops { · 160 unmodified lines
161	struct snd_compr_metadata *metadata);	161	struct snd_compr_metadata *metadata);
162	int (trigger)(struct snd_compr_stream stream, int cmd);	162	int (trigger)(struct snd_compr_stream stream, int cmd);
163	int (pointer)(struct snd_compr_stream stream,	163	int (pointer)(struct snd_compr_stream stream,
164	struct snd_compr_tstamp *tstamp);	164	struct snd_compr_tstamp64 *tstamp);
165	int (copy)(struct snd_compr_stream stream, char __user *buf,	165	int (copy)(struct snd_compr_stream stream, char __user *buf,
166	size_t count);	166	size_t count);
167	int (mmap)(struct snd_compr_stream stream,	167	int (mmap)(struct snd_compr_stream stream,

include/sound/soc-component.h+2−2

include/sound/soc-dai.h+4−3

 			  size_t bytes);
 int snd_soc_dai_compr_pointer(struct snd_soc_dai *dai,
 			      struct snd_compr_stream *cstream,
-			      struct snd_compr_tstamp *tstamp);
+			      struct snd_compr_tstamp64 *tstamp);
 int snd_soc_dai_compr_set_metadata(struct snd_soc_dai *dai,
 				   struct snd_compr_stream *cstream,
 				   struct snd_compr_metadata *metadata);
 			struct snd_compr_metadata *, struct snd_soc_dai *);
 	int (*trigger)(struct snd_compr_stream *, int,
 			struct snd_soc_dai *);
-	int (*pointer)(struct snd_compr_stream *,
+	int (*pointer)(struct snd_compr_stream *stream,
-			struct snd_compr_tstamp *, struct snd_soc_dai *);
+		       struct snd_compr_tstamp64 *tstamp,
+		       struct snd_soc_dai *dai);
 	int (*ack)(struct snd_compr_stream *, size_t,
 			struct snd_soc_dai *);
 };

include/uapi/sound/compress_offload.h+19−0

@@ -56,6 +56,25 @@ struct snd_compr_tstamp { · 55 unmodified lines
56	__u32 sampling_rate;	56	__u32 sampling_rate;
57	} __attribute__((packed, aligned(4)));	57	} __attribute__((packed, aligned(4)));
58		58
		59	/**
		60	* struct snd_compr_tstamp64 - timestamp descriptor with fields in 64 bit
		61	* @byte_offset: Byte offset in ring buffer to DSP
		62	* @copied_total: Total number of bytes copied from/to ring buffer to/by DSP
		63	* @pcm_frames: Frames decoded or encoded by DSP. This field will evolve by
		64	* large steps and should only be used to monitor encoding/decoding
		65	* progress. It shall not be used for timing estimates.
		66	* @pcm_io_frames: Frames rendered or received by DSP into a mixer or an audio
		67	* output/input. This field should be used for A/V sync or time estimates.
		68	* @sampling_rate: sampling rate of audio
		69	*/
		70	struct snd_compr_tstamp64 {
		71	__u32 byte_offset;
		72	__u64 copied_total;
		73	__u64 pcm_frames;
		74	__u64 pcm_io_frames;
		75	__u32 sampling_rate;
		76	} __attribute__((packed, aligned(4)));
		77
59	/**	78	/**
60	* struct snd_compr_avail - avail descriptor	79	* struct snd_compr_avail - avail descriptor
61	* @avail: Number of bytes available in ring buffer for writing/reading	80	* @avail: Number of bytes available in ring buffer for writing/reading

ALSA: compress_offload: Add 64-bit safe timestamp infrastructure

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@@ -47,7 +47,7 @@ struct snd_compress_ops { · 46 unmodified lines
47	struct snd_compr_stream *stream, int cmd);	47	struct snd_compr_stream *stream, int cmd);
48	int (pointer)(struct snd_soc_component component,	48	int (pointer)(struct snd_soc_component component,
49	struct snd_compr_stream *stream,	49	struct snd_compr_stream *stream,
50	struct snd_compr_tstamp *tstamp);	50	struct snd_compr_tstamp64 *tstamp);
51	int (copy)(struct snd_soc_component component,	51	int (copy)(struct snd_soc_component component,
52	struct snd_compr_stream stream, char __user buf,	52	struct snd_compr_stream stream, char __user buf,
53	size_t count);	53	size_t count);
@@ -498,7 +498,7 @@ int snd_soc_component_compr_get_codec_caps(struct snd_compr_stream *cstream, · 444 unmodified lines
498	struct snd_compr_codec_caps *codec);	498	struct snd_compr_codec_caps *codec);
499	int snd_soc_component_compr_ack(struct snd_compr_stream *cstream, size_t bytes);	499	int snd_soc_component_compr_ack(struct snd_compr_stream *cstream, size_t bytes);
500	int snd_soc_component_compr_pointer(struct snd_compr_stream *cstream,	500	int snd_soc_component_compr_pointer(struct snd_compr_stream *cstream,
501	struct snd_compr_tstamp *tstamp);	501	struct snd_compr_tstamp64 *tstamp);
502	int snd_soc_component_compr_copy(struct snd_compr_stream *cstream,	502	int snd_soc_component_compr_copy(struct snd_compr_stream *cstream,
503	char __user *buf, size_t count);	503	char __user *buf, size_t count);
504	int snd_soc_component_compr_set_metadata(struct snd_compr_stream *cstream,	504	int snd_soc_component_compr_set_metadata(struct snd_compr_stream *cstream,