video/pipewire: added upstream patch to better detect alsa devices

3 files changed, 169 insertions, 0 deletions

diff --git a/video/pipewire/HISTORY b/video/pipewire/HISTORY
index d92c8ebb19..b56e9ffe46 100644
--- a/video/pipewire/HISTORY
+++ b/video/pipewire/HISTORY
@@ -1,3 +1,7 @@
+2022-02-04 Pavel Vinogradov <public@sourcemage.org>
+	* PRE_BUILD, patches/alsa-udev.patch: added upstream patch to better detect
+	  alsa devices
+
 2022-02-03 Treeve Jelbert <treeve@sourcemage.org>
 	* DETAILS: version 0.3.45
 
diff --git a/video/pipewire/PRE_BUILD b/video/pipewire/PRE_BUILD
new file mode 100755
index 0000000000..005bf6d040
--- /dev/null
+++ b/video/pipewire/PRE_BUILD
@@ -0,0 +1,4 @@
+default_pre_build  &&
+cd "${SOURCE_DIRECTORY}" &&
+
+apply_patch_dir patches
diff --git a/video/pipewire/patches/alsa-udev.patch b/video/pipewire/patches/alsa-udev.patch
new file mode 100644
index 0000000000..b6d72883bf
--- /dev/null
+++ b/video/pipewire/patches/alsa-udev.patch
@@ -0,0 +1,161 @@
+From 97a5fe80c1d0fb0d8173a61a87051053cff7a5c2 Mon Sep 17 00:00:00 2001
+From: Pauli Virtanen <pav@iki.fi>
+Date: Thu, 3 Feb 2022 19:23:23 +0200
+Subject: [PATCH] spa/alsa-udev: fix /proc/asound handling without
+ CONFIG_SND_VERBOSE_PROCFS
+
+For kernels compiled with CONFIG_SND_VERBOSE_PROCFS=n, the pcmXX
+/proc/asound entries do not exist.  In that case, the "device busy"
+check cannot be done, but we should still check existence of PCM devices
+correctly.
+
+Count the number of PCM devices from /dev/snd, which should work also
+without /proc/asound or /sysfs/class/sound.
+---
+ spa/plugins/alsa/alsa-udev.c | 88 ++++++++++++++++++++++++++++++------
+ 1 file changed, 73 insertions(+), 15 deletions(-)
+
+diff --git a/spa/plugins/alsa/alsa-udev.c b/spa/plugins/alsa/alsa-udev.c
+index 572bb8a32..08373239d 100644
+--- a/spa/plugins/alsa/alsa-udev.c
++++ b/spa/plugins/alsa/alsa-udev.c
+@@ -246,6 +246,60 @@ static void unescape(const char *src, char *dst)
+ 	*d = 0;
+ }
+ 
++static int check_device_pcm_class(const char *devname)
++{
++	FILE *f;
++	char path[PATH_MAX];
++	char buf[16];
++	size_t sz;
++
++	/* Check device class */
++	spa_scnprintf(path, sizeof(path), "/sys/class/sound/%s/pcm_class",
++			devname);
++	f = fopen(path, "r");
++	if (f == NULL)
++		return -errno;
++	sz = fread(buf, 1, sizeof(buf) - 1, f);
++	buf[sz] = '\0';
++	fclose(f);
++	return spa_strstartswith(buf, "modem") ? -ENXIO : 0;
++}
++
++static int get_num_pcm_devices(unsigned int card_id)
++{
++	char prefix[32];
++	DIR *snd = NULL;
++	struct dirent *entry;
++	int num_dev = 0;
++	int res;
++
++	/* Check if card has PCM devices, without opening them */
++
++	spa_scnprintf(prefix, sizeof(prefix), "pcmC%uD", card_id);
++
++	if ((snd = opendir("/dev/snd")) == NULL)
++		return -errno;
++
++	while ((errno = 0, entry = readdir(snd)) != NULL) {
++		if (!(entry->d_type == DT_CHR &&
++				spa_strstartswith(entry->d_name, prefix)))
++			continue;
++
++		res = check_device_pcm_class(entry->d_name);
++		if (res == 0 || res == -ENOENT) {
++			/* count device also if sysfs status file not there */
++			++num_dev;
++		}
++	}
++	if (errno != 0)
++		res = -errno;
++	else
++		res = num_dev;
++
++	closedir(snd);
++	return res;
++}
++
+ static int check_device_available(struct impl *this, struct device *device, int *num_pcm)
+ {
+ 	char path[PATH_MAX];
+@@ -256,14 +310,26 @@ static int check_device_available(struct impl *this, struct device *device, int
+ 	struct dirent *entry, *entry_pcm;
+ 	int res;
+ 
++	res = get_num_pcm_devices(device->id);
++	if (res < 0) {
++		spa_log_error(this->log, "Error finding PCM devices for ALSA card %u: %s",
++			(unsigned int)device->id, spa_strerror(res));
++		return res;
++	}
++	*num_pcm = res;
++
++	spa_log_debug(this->log, "card %u has %d pcm device(s)", (unsigned int)device->id, *num_pcm);
++
+ 	/*
+ 	 * Check if some pcm devices of the card are busy.  Check it via /proc, as we
+ 	 * don't want to actually open any devices using alsa-lib (generates uncontrolled
+ 	 * number of inotify events), or replicate its subdevice logic.
++	 *
++	 * The pcmXX directories do not exist if kernel is compiled with
++	 * CONFIG_SND_VERBOSE_PROCFS=n. In that case, the busy check always
++	 * succeeds.
+ 	 */
+ 
+-	*num_pcm = 0;
+-
+ 	spa_scnprintf(path, sizeof(path), "/proc/asound/card%u", (unsigned int)device->id);
+ 
+ 	if ((card = opendir(path)) == NULL)
+@@ -274,16 +340,9 @@ static int check_device_available(struct impl *this, struct device *device, int
+ 				spa_strstartswith(entry->d_name, "pcm")))
+ 			continue;
+ 
+-		/* Check device class */
+-		spa_scnprintf(path, sizeof(path), "/sys/class/sound/pcmC%uD%s/pcm_class",
++		spa_scnprintf(path, sizeof(path), "pcmC%uD%s",
+ 				(unsigned int)device->id, entry->d_name+3);
+-		f = fopen(path, "r");
+-		if (f == NULL)
+-			goto done;
+-		sz = fread(buf, 1, sizeof(buf) - 1, f);
+-		buf[sz] = '\0';
+-		fclose(f);
+-		if (spa_strstartswith(buf, "modem"))
++		if (check_device_pcm_class(path) < 0)
+ 			continue;
+ 
+ 		/* Check busy status */
+@@ -319,8 +378,6 @@ static int check_device_available(struct impl *this, struct device *device, int
+ 		if (errno != 0)
+ 			goto done;
+ 
+-		++*num_pcm;
+-
+ 		closedir(pcm);
+ 		pcm = NULL;
+ 	}
+@@ -352,15 +409,16 @@ static int emit_object_info(struct impl *this, struct device *device)
+ 	 * device->emitted to true. alsalib functions can be used after that.
+ 	 */
+ 
++	snprintf(path, sizeof(path), "hw:%u", id);
++
+ 	if ((res = check_device_available(this, device, &pcm)) < 0)
+ 		return res;
+ 	if (pcm == 0) {
+ 		spa_log_debug(this->log, "no pcm devices for %s", path);
+ 		device->ignored = true;
+-		return 0;
++		return -ENODEV;
+ 	}
+ 
+-	snprintf(path, sizeof(path), "hw:%u", id);
+ 	spa_log_debug(this->log, "emitting card %s", path);
+ 	device->emitted = true;
+ 
+-- 
+GitLab
+