linux/sound/usb/card.h
Takashi Iwai 5a6c3e11c9 ALSA: usb-audio: Add hw constraint for implicit fb sync
In the current code, there is no check at the stream open time whether
the endpoint is being already used by others.  In the normal
operations, this shouldn't happen, but in the case of the implicit
feedback mode, it's a common problem with the full duplex operation,
because the capture stream is always opened by the playback stream as
an implicit sync source.

Although we recently introduced the check of such a conflict of
parameters at the PCM hw_params time, it doesn't give any hint at the
hw_params itself and just gives the error.  This isn't quite
comfortable, and it caused problems on many applications.

This patch attempts to make the parameter handling easier by
introducing the strict hw constraint matching with the counterpart
stream that is being used.  That said, when an implicit feedback
playback stream is running before a capture stream is opened, the
capture stream carries the PCM hw-constraint to allow only the same
sample rate, format, periods and period frames as the running playback
stream.  If not opened or there is no conflict of endpoints, the
behavior remains as same as before.

Note that this kind of "weak link" should work for most cases, but
this is no concrete solution; e.g. if an application changes the hw
params multiple times while another stream is opened, this would lead
to inconsistencies.

Tested-by: Keith Milner <kamilner@superlative.org>
Tested-by: Dylan Robinson <dylan_robinson@motu.com>
Link: https://lore.kernel.org/r/20201123085347.19667-11-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-11-23 15:12:46 +01:00

198 lines
7.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __USBAUDIO_CARD_H
#define __USBAUDIO_CARD_H
#define MAX_NR_RATES 1024
#define MAX_PACKS 6 /* per URB */
#define MAX_PACKS_HS (MAX_PACKS * 8) /* in high speed mode */
#define MAX_URBS 12
#define SYNC_URBS 4 /* always four urbs for sync */
#define MAX_QUEUE 18 /* try not to exceed this queue length, in ms */
struct audioformat {
struct list_head list;
u64 formats; /* ALSA format bits */
unsigned int channels; /* # channels */
unsigned int fmt_type; /* USB audio format type (1-3) */
unsigned int fmt_bits; /* number of significant bits */
unsigned int frame_size; /* samples per frame for non-audio */
int iface; /* interface number */
unsigned char altsetting; /* corresponding alternate setting */
unsigned char altset_idx; /* array index of altenate setting */
unsigned char attributes; /* corresponding attributes of cs endpoint */
unsigned char endpoint; /* endpoint */
unsigned char ep_attr; /* endpoint attributes */
bool implicit_fb; /* implicit feedback endpoint */
unsigned char sync_ep; /* sync endpoint number */
unsigned char sync_iface; /* sync EP interface */
unsigned char sync_altsetting; /* sync EP alternate setting */
unsigned char datainterval; /* log_2 of data packet interval */
unsigned char protocol; /* UAC_VERSION_1/2/3 */
unsigned int maxpacksize; /* max. packet size */
unsigned int rates; /* rate bitmasks */
unsigned int rate_min, rate_max; /* min/max rates */
unsigned int nr_rates; /* number of rate table entries */
unsigned int *rate_table; /* rate table */
unsigned char clock; /* associated clock */
struct snd_pcm_chmap_elem *chmap; /* (optional) channel map */
bool dsd_dop; /* add DOP headers in case of DSD samples */
bool dsd_bitrev; /* reverse the bits of each DSD sample */
bool dsd_raw; /* altsetting is raw DSD */
};
struct snd_usb_substream;
struct snd_usb_endpoint;
struct snd_usb_power_domain;
struct snd_urb_ctx {
struct urb *urb;
unsigned int buffer_size; /* size of data buffer, if data URB */
struct snd_usb_substream *subs;
struct snd_usb_endpoint *ep;
int index; /* index for urb array */
int packets; /* number of packets per urb */
int packet_size[MAX_PACKS_HS]; /* size of packets for next submission */
struct list_head ready_list;
};
struct snd_usb_endpoint {
struct snd_usb_audio *chip;
int use_count;
int ep_num; /* the referenced endpoint number */
int type; /* SND_USB_ENDPOINT_TYPE_* */
unsigned long flags;
void (*prepare_data_urb) (struct snd_usb_substream *subs,
struct urb *urb);
void (*retire_data_urb) (struct snd_usb_substream *subs,
struct urb *urb);
struct snd_usb_substream *data_subs;
struct snd_usb_endpoint *sync_master;
struct snd_usb_endpoint *sync_slave;
struct snd_urb_ctx urb[MAX_URBS];
struct snd_usb_packet_info {
uint32_t packet_size[MAX_PACKS_HS];
int packets;
} next_packet[MAX_URBS];
int next_packet_read_pos, next_packet_write_pos;
struct list_head ready_playback_urbs;
unsigned int nurbs; /* # urbs */
unsigned long active_mask; /* bitmask of active urbs */
unsigned long unlink_mask; /* bitmask of unlinked urbs */
char *syncbuf; /* sync buffer for all sync URBs */
dma_addr_t sync_dma; /* DMA address of syncbuf */
unsigned int pipe; /* the data i/o pipe */
unsigned int packsize[2]; /* small/large packet sizes in samples */
unsigned int sample_rem; /* remainder from division fs/pps */
unsigned int sample_accum; /* sample accumulator */
unsigned int pps; /* packets per second */
unsigned int freqn; /* nominal sampling rate in fs/fps in Q16.16 format */
unsigned int freqm; /* momentary sampling rate in fs/fps in Q16.16 format */
int freqshift; /* how much to shift the feedback value to get Q16.16 */
unsigned int freqmax; /* maximum sampling rate, used for buffer management */
unsigned int phase; /* phase accumulator */
unsigned int maxpacksize; /* max packet size in bytes */
unsigned int maxframesize; /* max packet size in frames */
unsigned int max_urb_frames; /* max URB size in frames */
unsigned int curpacksize; /* current packet size in bytes (for capture) */
unsigned int curframesize; /* current packet size in frames (for capture) */
unsigned int syncmaxsize; /* sync endpoint packet size */
unsigned int fill_max:1; /* fill max packet size always */
unsigned int tenor_fb_quirk:1; /* corrupted feedback data */
unsigned int datainterval; /* log_2 of data packet interval */
unsigned int syncinterval; /* P for adaptive mode, 0 otherwise */
unsigned char silence_value;
unsigned int stride;
int iface, altsetting;
int skip_packets; /* quirks for devices to ignore the first n packets
in a stream */
bool is_implicit_feedback; /* This endpoint is used as implicit feedback */
/* for hw constraints */
unsigned int cur_rate;
snd_pcm_format_t cur_format;
unsigned int cur_channels;
unsigned int cur_period_frames;
unsigned int cur_period_bytes;
unsigned int cur_buffer_periods;
spinlock_t lock;
struct list_head list;
};
struct media_ctl;
struct snd_usb_substream {
struct snd_usb_stream *stream;
struct usb_device *dev;
struct snd_pcm_substream *pcm_substream;
int direction; /* playback or capture */
int interface; /* current interface */
int endpoint; /* assigned endpoint */
struct audioformat *cur_audiofmt; /* current audioformat pointer (for hw_params callback) */
struct snd_usb_power_domain *str_pd; /* UAC3 Power Domain for streaming path */
snd_pcm_format_t pcm_format; /* current audio format (for hw_params callback) */
unsigned int channels; /* current number of channels (for hw_params callback) */
unsigned int channels_max; /* max channels in the all audiofmts */
unsigned int cur_rate; /* current rate (for hw_params callback) */
unsigned int period_bytes; /* current period bytes (for hw_params callback) */
unsigned int period_frames; /* current frames per period */
unsigned int buffer_periods; /* current periods per buffer */
unsigned int altset_idx; /* USB data format: index of alternate setting */
unsigned int txfr_quirk:1; /* allow sub-frame alignment */
unsigned int tx_length_quirk:1; /* add length specifier to transfers */
unsigned int fmt_type; /* USB audio format type (1-3) */
unsigned int pkt_offset_adj; /* Bytes to drop from beginning of packets (for non-compliant devices) */
unsigned int stream_offset_adj; /* Bytes to drop from beginning of stream (for non-compliant devices) */
unsigned int running: 1; /* running status */
unsigned int fixed_hw:1; /* fixed hw constraints due to sync EP */
unsigned int hwptr_done; /* processed byte position in the buffer */
unsigned int transfer_done; /* processed frames since last period update */
unsigned int frame_limit; /* limits number of packets in URB */
/* data and sync endpoints for this stream */
unsigned int ep_num; /* the endpoint number */
struct snd_usb_endpoint *data_endpoint;
struct snd_usb_endpoint *sync_endpoint;
unsigned long flags;
bool need_setup_ep; /* (re)configure EP at prepare? */
bool need_setup_fmt; /* (re)configure fmt after resume? */
unsigned int speed; /* USB_SPEED_XXX */
u64 formats; /* format bitmasks (all or'ed) */
unsigned int num_formats; /* number of supported audio formats (list) */
struct list_head fmt_list; /* format list */
spinlock_t lock;
int last_frame_number; /* stored frame number */
int last_delay; /* stored delay */
struct {
int marker;
int channel;
int byte_idx;
} dsd_dop;
bool trigger_tstamp_pending_update; /* trigger timestamp being updated from initial estimate */
struct media_ctl *media_ctl;
};
struct snd_usb_stream {
struct snd_usb_audio *chip;
struct snd_pcm *pcm;
int pcm_index;
unsigned int fmt_type; /* USB audio format type (1-3) */
struct snd_usb_substream substream[2];
struct list_head list;
};
#endif /* __USBAUDIO_CARD_H */