[alsa-devel] [PATCH - alsa-lib 1/1] Introduce snd_seq_client_info_get_card_number, for getting the card number of a seq client on recent kernels
Signed-off-by: Adam Goode agoode@google.com
diff --git a/configure.ac b/configure.ac index 9621d4e..01bb0fb 100644 --- a/configure.ac +++ b/configure.ac @@ -14,7 +14,7 @@ dnl remove API = c+1:0:0 dnl ************************************************* AC_CANONICAL_HOST AM_INIT_AUTOMAKE -eval LIBTOOL_VERSION_INFO="2:0:0" +eval LIBTOOL_VERSION_INFO="3:0:1" dnl ************************************************* AM_CONDITIONAL([INSTALL_M4], [test -n "${ACLOCAL}"])
diff --git a/include/seq.h b/include/seq.h index 9576822..e0f9b78 100644 --- a/include/seq.h +++ b/include/seq.h @@ -146,6 +146,7 @@ int snd_seq_client_info_get_error_bounce(const snd_seq_client_info_t *info); const unsigned char *snd_seq_client_info_get_event_filter(const snd_seq_client_info_t *info); int snd_seq_client_info_get_num_ports(const snd_seq_client_info_t *info); int snd_seq_client_info_get_event_lost(const snd_seq_client_info_t *info); +int snd_seq_client_info_get_card_number(const snd_seq_client_info_t *info);
void snd_seq_client_info_set_client(snd_seq_client_info_t *info, int client); void snd_seq_client_info_set_name(snd_seq_client_info_t *info, const char *name); diff --git a/include/sound/asequencer.h b/include/sound/asequencer.h index 09c8a00..c2a659b 100644 --- a/include/sound/asequencer.h +++ b/include/sound/asequencer.h @@ -22,9 +22,10 @@ #ifndef _UAPI__SOUND_ASEQUENCER_H #define _UAPI__SOUND_ASEQUENCER_H
+#include <sound/asound.h>
/** version of the sequencer */ -#define SNDRV_SEQ_VERSION SNDRV_PROTOCOL_VERSION (1, 0, 1) +#define SNDRV_SEQ_VERSION SNDRV_PROTOCOL_VERSION (1, 0, 2)
/** * definition of sequencer event types @@ -356,7 +357,8 @@ struct snd_seq_client_info { unsigned char event_filter[32]; /* event filter bitmap */ int num_ports; /* RO: number of ports */ int event_lost; /* number of lost events */ - char reserved[64]; /* for future use */ + int card_number; /* RO: card number, or -1 if no card. Added in protocol version 1.0.2 */ + char reserved[60]; /* for future use */ };
diff --git a/src/seq/seq.c b/src/seq/seq.c index 620ca3f..bc39046 100644 --- a/src/seq/seq.c +++ b/src/seq/seq.c @@ -1651,6 +1651,18 @@ int snd_seq_client_info_get_event_lost(const snd_seq_client_info_t *info) }
/** + * \brief Get the card number of a client_info container + * \param info client_info container + * \return the card number, -1 if no card associated with this client, or -ENOSYS if the + * kernel does not support reporting this field + */ +int snd_seq_client_info_get_card_number(const snd_seq_client_info_t *info) +{ + assert(info); + return info->card_number; +} + +/** * \brief Set the client id of a client_info container * \param info client_info container * \param client client id diff --git a/src/seq/seq_hw.c b/src/seq/seq_hw.c index d033367..8502d63 100644 --- a/src/seq/seq_hw.c +++ b/src/seq/seq_hw.c @@ -32,10 +32,11 @@ const char *_snd_module_seq_hw = ""; #ifndef DOC_HIDDEN #define SNDRV_FILE_SEQ ALSA_DEVICE_DIRECTORY "seq" #define SNDRV_FILE_ALOADSEQ ALOAD_DEVICE_DIRECTORY "aloadSEQ" -#define SNDRV_SEQ_VERSION_MAX SNDRV_PROTOCOL_VERSION(1, 0, 1) +#define SNDRV_SEQ_VERSION_MAX SNDRV_PROTOCOL_VERSION(1, 0, 2)
typedef struct { int fd; + int version; } snd_seq_hw_t; #endif /* DOC_HIDDEN */
@@ -100,6 +101,10 @@ static int snd_seq_hw_get_client_info(snd_seq_t *seq, snd_seq_client_info_t * in /*SYSERR("SNDRV_SEQ_IOCTL_GET_CLIENT_INFO failed");*/ return -errno; } + /* The card_number field was added in protocol 1.0.2, so set to -ENOSYS if older. */ + if (hw->version < SNDRV_PROTOCOL_VERSION(1, 0, 2)) { + info->card_number = -ENOSYS; + } return 0; }
@@ -368,6 +373,10 @@ static int snd_seq_hw_query_next_client(snd_seq_t *seq, snd_seq_client_info_t *i /*SYSERR("SNDRV_SEQ_IOCTL_QUERY_NEXT_CLIENT failed");*/ return -errno; } + /* The card_number field was added in protocol 1.0.2, so set to -ENOSYS if older. */ + if (hw->version < SNDRV_PROTOCOL_VERSION(1, 0, 2)) { + info->card_number = -ENOSYS; + } return 0; }
@@ -480,6 +489,7 @@ int snd_seq_hw_open(snd_seq_t **handle, const char *name, int streams, int mode) return -ENOMEM; } hw->fd = fd; + hw->version = ver; if (streams & SND_SEQ_OPEN_OUTPUT) { seq->obuf = (char *) malloc(seq->obufsize = SND_SEQ_OBUF_SIZE); if (!seq->obuf) { diff --git a/test/seq.c b/test/seq.c index 34b000f..a4e5f1f 100644 --- a/test/seq.c +++ b/test/seq.c @@ -111,7 +111,7 @@ void show_port_info(snd_seq_t *handle, int client, int port)
void show_client_info(snd_seq_t *handle, int client) { - int err, idx, min, max; + int err, idx, min, max, card_number; snd_seq_client_info_t *info;
snd_seq_client_info_alloca(&info); @@ -124,11 +124,14 @@ void show_client_info(snd_seq_t *handle, int client) fprintf(stderr, "Client %i info error: %s\n", idx, snd_strerror(err)); exit(0); } + card_number = snd_seq_client_info_get_card_number(info); printf("Client %i info\n", idx); if (verbose) printf(" Client : %i\n", snd_seq_client_info_get_client(info)); printf(" Type : %s\n", snd_seq_client_info_get_type(info) == SND_SEQ_KERNEL_CLIENT ? "kernel" : "user"); printf(" Name : %s\n", snd_seq_client_info_get_name(info)); + if (card_number != -ENOSYS) + printf(" Card Number : %i\n", card_number); } }
Adam Goode wrote:
/**
- \brief Get the card number of a client_info container
- \param info client_info container
- \return the card number, -1 if no card associated with this client, or -ENOSYS if the
kernel does not support reporting this field
- */
-1 is used as an out-of-range value when enumerating cards. However, I don't think this convention can be applied here, because the return value is also used for error codes, and -1 would correspond to -EPERM.
Squashing all error codes into -1 is not a good idea, so I think the value -1 should be converted into an appropriate error code, probably -ENXIO.
Regards, Clemens
At Fri, 05 Jun 2015 08:50:45 +0200, Clemens Ladisch wrote:
Adam Goode wrote:
/**
- \brief Get the card number of a client_info container
- \param info client_info container
- \return the card number, -1 if no card associated with this client, or -ENOSYS if the
kernel does not support reporting this field
- */
-1 is used as an out-of-range value when enumerating cards. However, I don't think this convention can be applied here, because the return value is also used for error codes, and -1 would correspond to -EPERM.
Squashing all error codes into -1 is not a good idea, so I think the value -1 should be converted into an appropriate error code, probably -ENXIO.
Agreed.
Also, please don't include irrelevant changes in configure.ac.
thanks,
Takashi
On Wed, Jun 10, 2015 at 6:35 AM, Takashi Iwai tiwai@suse.de wrote:
At Fri, 05 Jun 2015 08:50:45 +0200, Clemens Ladisch wrote:
Adam Goode wrote:
/**
- \brief Get the card number of a client_info container
- \param info client_info container
- \return the card number, -1 if no card associated with this
client, or -ENOSYS if the
kernel does not support reporting this field
- */
-1 is used as an out-of-range value when enumerating cards. However, I don't think this convention can be applied here, because the return value is also used for error codes, and -1 would correspond to -EPERM.
Squashing all error codes into -1 is not a good idea, so I think the value -1 should be converted into an appropriate error code, probably -ENXIO.
Agreed.
Also, please don't include irrelevant changes in configure.ac.
thanks,
Takashi
Thanks for the feedback, I should have time this week to get back to you.
Adam
participants (3)
-
Adam Goode
-
Clemens Ladisch
-
Takashi Iwai