ALSA: seq: Provide card number / PID via sequencer client info

rawmidi devices expose the card number via IOCTLs, which allows to
find the corresponding device in sysfs.

The sequencer provides no identifing data. Chromium works around this
issue by scanning rawmidi as well as sequencer devices and matching
them by using assumtions, how the kernel register sequencer devices.

This changes adds support for exposing the card number for kernel clients
as well as the PID for user client.

The minor of the API version is changed to distinguish between the zero
initialised reserved field and card number 0.

[minor coding style fixes by tiwai]

Signed-off-by: Martin Koegler <martin.koegler@chello.at>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/include/uapi/sound/asequencer.h b/include/uapi/sound/asequencer.h
index af96f2044f91638a95c670525f7f06ff0d5c8b16..7b7659a79ac4c79cfac5061defb1af90e5c6f144 100644 (file)
--- a/include/uapi/sound/asequencer.h
+++ b/include/uapi/sound/asequencer.h
@@ -25,7 +25,7 @@
 #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
@@ -357,7 +357,9 @@ 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;                       /* RO: card number[kernel] */
+       int pid;                        /* RO: pid[user] */
+       char reserved[56];              /* for future use */
 };
 
 

diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c
index 58e79e02f2174e29f409cf129030af87d240dfce..d6d9419d8bacd28959a3b154ff76cdee54abaac4 100644 (file)
--- a/sound/core/seq/seq_clientmgr.c
+++ b/sound/core/seq/seq_clientmgr.c
@@ -364,6 +364,7 @@ static int snd_seq_open(struct inode *inode, struct file *file)
        /* fill client data */
        user->file = file;
        sprintf(client->name, "Client-%d", c);
+       client->data.user.owner = get_pid(task_pid(current));
 
        /* make others aware this new client */
        snd_seq_system_client_ev_client_start(c);
@@ -380,6 +381,7 @@ static int snd_seq_release(struct inode *inode, struct file *file)
                seq_free_client(client);
                if (client->data.user.fifo)
                        snd_seq_fifo_delete(&client->data.user.fifo);
+               put_pid(client->data.user.owner);
                kfree(client);
        }
 
@@ -1197,6 +1199,17 @@ static void get_client_info(struct snd_seq_client *cptr,
        info->event_lost = cptr->event_lost;
        memcpy(info->event_filter, cptr->event_filter, 32);
        info->num_ports = cptr->num_ports;
+
+       if (cptr->type == USER_CLIENT)
+               info->pid = pid_vnr(cptr->data.user.owner);
+       else
+               info->pid = -1;
+
+       if (cptr->type == KERNEL_CLIENT)
+               info->card = cptr->data.kernel.card ? cptr->data.kernel.card->number : -1;
+       else
+               info->card = -1;
+
        memset(info->reserved, 0, sizeof(info->reserved));
 }
 
@@ -2271,6 +2284,7 @@ int snd_seq_create_kernel_client(struct snd_card *card, int client_index,
 
        client->accept_input = 1;
        client->accept_output = 1;
+       client->data.kernel.card = card;
                
        va_start(args, name_fmt);
        vsnprintf(client->name, sizeof(client->name), name_fmt, args);

diff --git a/sound/core/seq/seq_clientmgr.h b/sound/core/seq/seq_clientmgr.h
index 20f0a725ec7db293a1edc18c83af60fe3ab11d34..c6614254ef8af2f56b68193dc4ce4d35d49b3773 100644 (file)
--- a/sound/core/seq/seq_clientmgr.h
+++ b/sound/core/seq/seq_clientmgr.h
@@ -33,6 +33,7 @@
 struct snd_seq_user_client {
        struct file *file;      /* file struct of client */
        /* ... */
+       struct pid *owner;
        
        /* fifo */
        struct snd_seq_fifo *fifo;      /* queue for incoming events */
@@ -41,6 +42,7 @@ struct snd_seq_user_client {
 
 struct snd_seq_kernel_client {
        /* ... */
+       struct snd_card *card;
 };