From c725e2bb941ca340529401e1f6efbde3113a9d94 Mon Sep 17 00:00:00 2001 From: Preston Baxter Date: Sat, 3 Aug 2024 14:27:54 -0500 Subject: [PATCH] Recieved a message in kernel space --- aes67.c | 101 +++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 82 insertions(+), 19 deletions(-) diff --git a/aes67.c b/aes67.c index 9c9843f..40f2f85 100644 --- a/aes67.c +++ b/aes67.c @@ -5,6 +5,7 @@ * */ #include +#include #include #include #include @@ -22,6 +23,9 @@ static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP; static int pcm_devs[SNDRV_CARDS] = { [0 ...(SNDRV_CARDS - 1)] = 1 }; static int pcm_substreams[SNDRV_CARDS] = { [0 ...(SNDRV_CARDS - 1)] = 8 }; +/* work for the network streams */ +static struct workqueue_struct *io_workqueue; + static struct platform_device *devices[SNDRV_CARDS]; #define CARD_NAME "AES67 Virtual Soundcard" @@ -55,12 +59,19 @@ struct aes67 { struct socket *socket; /* Receiving Work Queue */ + spinlock_t rlock; struct work_struct receive_work; + bool rx_on; }; //Forward declarations static int snd_aes67_new_pcm(struct aes67 *virtcard); +static int work_start(void); +static void work_stop(void); + +static void aes67_rx_net(struct work_struct *rwork); + /* Destructor */ static int snd_aes67_free(struct aes67 *virtcard) { @@ -136,6 +147,11 @@ static int snd_aes67_create(struct snd_card *card, struct aes67 **rvirtcard) return err; } + /* Spin lock for receiving */ + spin_lock_init(&virtcard->rlock); + /* Init work for card */ + INIT_WORK(&virtcard->receive_work, aes67_rx_net); + /* Add PCM */ err = snd_aes67_new_pcm(virtcard); if (err < 0) { @@ -194,6 +210,27 @@ error: snd_card_free(card); return err; } +/* Work queue Management */ +static void work_stop(void) +{ + if (io_workqueue) { + destroy_workqueue(io_workqueue); + io_workqueue = NULL; + } +} + +static int work_start(void) +{ + io_workqueue = alloc_workqueue("aes67_io", WQ_HIGHPRI | WQ_MEM_RECLAIM | + WQ_UNBOUND, 0); + + if (!io_workqueue) { + snd_printk(KERN_ERR "Failed to start io workqueue struct\n"); + return -ENOMEM; + } + return 0; +} + /* Network functions */ static void aes67_rx_net(struct work_struct *work) @@ -202,9 +239,8 @@ static void aes67_rx_net(struct work_struct *work) struct kvec iv; struct msghdr msg = {}; size_t recv_buf_size = 4096; - int ret, buflen; - void *recv_buf; - /* Read lock socket */ + ssize_t msglen; + unsigned char *recv_buf; /* Loop Receive */ recv_buf = kzalloc(recv_buf_size, GFP_KERNEL); @@ -214,14 +250,35 @@ static void aes67_rx_net(struct work_struct *work) return; } - do { + msg.msg_flags = MSG_PEEK | MSG_DONTWAIT; + + snd_printk(KERN_INFO "Starting network receive loop\n"); + for (;;) { iv.iov_base = recv_buf; iv.iov_len = recv_buf_size; - msglen = kernel_recvmsg(virtcard->socket, &msg, &iv, 1, iv.iov_len, MSG_DONTWAIT); + msglen = kernel_recvmsg(virtcard->socket, &msg, &iv, 1, + iv.iov_len, msg.msg_flags); - } while (ret == AES67_NET_SUCCESS); + if (msglen == -EAGAIN) { + snd_printk( + KERN_WARNING + "Failed to receive message. With EAGAIN, Sleeping and trying again\n"); + msleep(1000); + continue; + } + if (msglen < 0) { + snd_printk(KERN_ERR "error receiving packet: %zd\n", + msglen); + break; + } + + if (msglen > 0) { + snd_printk(KERN_INFO "Received Buffer: %ph", recv_buf); + break; + } + } /* Handle stream end */ snd_printk(KERN_INFO "Finished Receiving work queue\n"); @@ -265,8 +322,16 @@ static struct snd_pcm_hardware snd_aes67_capture_hw = { static int snd_aes67_playback_open(struct snd_pcm_substream *substream) { - struct aes67 *virtcard = snd_pcm_substream_chip(substream); struct snd_pcm_runtime *runtime = substream->runtime; + struct aes67 *chip = snd_pcm_substream_chip(substream); + + spin_lock_irq(&chip->rlock); + if (!chip->rx_on) { + snd_printk(KERN_INFO "Starting receive work queue\n"); + queue_work(io_workqueue, &chip->receive_work); + chip->rx_on = true; + } + spin_unlock_irq(&chip->rlock); runtime->hw = snd_aes67_playback_hw; return 0; @@ -274,13 +339,11 @@ static int snd_aes67_playback_open(struct snd_pcm_substream *substream) static int snd_aes67_playback_close(struct snd_pcm_substream *substream) { - struct aes67 *virtcard = snd_pcm_substream_chip(substream); return 0; } static int snd_aes67_capture_open(struct snd_pcm_substream *substream) { - struct aes67 *virtcard = snd_pcm_substream_chip(substream); struct snd_pcm_runtime *runtime = substream->runtime; runtime->hw = snd_aes67_capture_hw; @@ -289,7 +352,6 @@ static int snd_aes67_capture_open(struct snd_pcm_substream *substream) static int snd_aes67_capture_close(struct snd_pcm_substream *substream) { - struct aes67 *virtcard = snd_pcm_substream_chip(substream); return 0; } @@ -309,9 +371,6 @@ static int snd_aes67_pcm_hw_free(struct snd_pcm_substream *substream) static int snd_aes67_pcm_prepare(struct snd_pcm_substream *substream) { - struct aes67 *chip = snd_pcm_substream_chip(substream); - struct snd_pcm_runtime *runtime = substream->runtime; - /* set up the hardware with the current configuration * for example... */ @@ -320,13 +379,8 @@ static int snd_aes67_pcm_prepare(struct snd_pcm_substream *substream) static int snd_aes67_pcm_trigger(struct snd_pcm_substream *substream, int cmd) { - struct aes67 *chip = snd_pcm_substream_chip(substream); - - int err; - switch (cmd) { case SNDRV_PCM_TRIGGER_START: - INIT_WORK(&chip->receive_work, aes67_rx_net); break; case SNDRV_PCM_TRIGGER_STOP: /* do something to stop the PCM engine */ @@ -402,7 +456,7 @@ static int snd_aes67_new_pcm(struct aes67 *virtcard) /*Da buffers*/ snd_printk(KERN_INFO "Settig PCM managed buffer"); snd_pcm_set_managed_buffer_all(pcm, SNDRV_DEV_LOWLEVEL, virtcard->dev, - 64 * 1024, 64 * 1024); + 32 * 1024, 32 * 1024); return 0; } @@ -449,6 +503,13 @@ static int __init alsa_card_aes67_init(void) return err; } + /* Start work queue */ + err = work_start(); + if (err < 0) { + snd_printk(KERN_ERR "FAILED to start workqueue for AES67\n"); + return err; + } + //register a card in the kernel struct platform_device *device; device = platform_device_register_simple(SND_AES67_DRIVER, 0, NULL, 0); @@ -468,6 +529,8 @@ static int __init alsa_card_aes67_init(void) static void __exit alsa_card_aes67_exit(void) { + snd_printk(KERN_INFO "Attempting to stop workqueue for AES67\n"); + work_stop(); snd_printk(KERN_INFO "Attempting to unregister card for AES67\n"); platform_device_unregister(devices[0]); snd_printk(KERN_INFO "Attempting to unregistered driver for AES67\n");