Merge tag 'sound-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound

Pull sound updates from Takashi Iwai:
 "As the diffstat shows, we've had lots of developments in a wide range
  at this time; the majority of changes are about ASoC, including
  subsystem-wide cleanups, continued SOF / Intel updates and a bunch of
  new drivers (as usual), while there have been some significant (but
  almost invisible) improvements in ALSA core side, too.

  Below are some highlights:

  Core:

   - Faster lookups of control elements with Xarray; normal user won't
     notice, but on the devices with tons of control elements, it can be
     visibly faster

   - Support for input validation for controls; this will harden for
     badly written drivers in general with a slight overhead

   - Deferred async signal handling for working around the potential
     deadlocks

   - Cleanup / refactoring raw MIDI locking code

  ASoC:

   - Restructing of the set_fmt() callbacks for making things clearer in
     situations like CODEC to CODEC links

   - Clean up and modernizing the DAI naming scheme setups

   - Merge of more of the Intel AVS driver stack, including some board
     integrations

   - New version 4 mechanism for communication with SOF DSPs

   - Suppoort for dynamically selecting the PLL to use at runtime on
     i.MX platforms

   - Improvements for CODEC to CODEC support in the generic cards

   - Support for AMD Jadeite and various machines, AMD RPL, Intel
     MetorLake DSPs, Mediatek MT8186 DSPs and MT6366, nVidia Tegra
     MDDRC, OPE and PEQ, NXP TFA9890, Qualcomm SDM845, WCD9335 and
     WAS883x, and Texas Instruments TAS2780

  HD- and USB-audio:

   - Continued improvement for CS35L41 (sub)codec support

   - More quirks for various devices (HP, Lenovo, Dell, Clevo)"

* tag 'sound-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (778 commits)
  ALSA: hda/realtek: Add quirk for HP Spectre x360 15-eb0xxx
  ALSA: line6: Replace sprintf() with sysfs_emit()
  ALSA: hda: Replace sprintf() with sysfs_emit()
  ALSA: pcm: Replace sprintf() with sysfs_emit()
  ALSA: core: Replace scnprintf() with sysfs_emit()
  ALSA: control-led: Replace sprintf() with sysfs_emit()
  ALSA: aoa: Replace sprintf() with sysfs_emit()
  ALSA: ac97: Replace sprintf() with sysfs_emit()
  ALSA: hda/realtek: Add quirk for Clevo NV45PZ
  ALSA: hda/realtek: Add quirk for Lenovo Yoga9 14IAP7
  ALSA: control: Use deferred fasync helper
  ALSA: pcm: Use deferred fasync helper
  ALSA: timer: Use deferred fasync helper
  ALSA: core: Add async signal helpers
  ASoC: q6asm: use kcalloc() instead of kzalloc()
  ACPI: scan: Add CLSA0101 Laptop Support
  ALSA: hda: cs35l41: Support CLSA0101
  ALSA: hda: cs35l41: Use the CS35L41 HDA internal define
  ASoC: dt-bindings: use spi-peripheral-props.yaml
  ASoC: codecs: va-macro: use fsgen as clock
  ...

1 files changed, 94 insertions, 0 deletions

diff --git a/sound/core/misc.c b/sound/core/misc.c
index 50e4aaa6270d..d32a19976a2b 100644
--- a/sound/core/misc.c
+++ b/sound/core/misc.c
@@ -10,6 +10,7 @@
 #include <linux/time.h>
 #include <linux/slab.h>
 #include <linux/ioport.h>
+#include <linux/fs.h>
 #include <sound/core.h>
 
 #ifdef CONFIG_SND_DEBUG
@@ -145,3 +146,96 @@ snd_pci_quirk_lookup(struct pci_dev *pci, const struct snd_pci_quirk *list)
 }
 EXPORT_SYMBOL(snd_pci_quirk_lookup);
 #endif
+
+/*
+ * Deferred async signal helpers
+ *
+ * Below are a few helper functions to wrap the async signal handling
+ * in the deferred work.  The main purpose is to avoid the messy deadlock
+ * around tasklist_lock and co at the kill_fasync() invocation.
+ * fasync_helper() and kill_fasync() are replaced with snd_fasync_helper()
+ * and snd_kill_fasync(), respectively.  In addition, snd_fasync_free() has
+ * to be called at releasing the relevant file object.
+ */
+struct snd_fasync {
+	struct fasync_struct *fasync;
+	int signal;
+	int poll;
+	int on;
+	struct list_head list;
+};
+
+static DEFINE_SPINLOCK(snd_fasync_lock);
+static LIST_HEAD(snd_fasync_list);
+
+static void snd_fasync_work_fn(struct work_struct *work)
+{
+	struct snd_fasync *fasync;
+
+	spin_lock_irq(&snd_fasync_lock);
+	while (!list_empty(&snd_fasync_list)) {
+		fasync = list_first_entry(&snd_fasync_list, struct snd_fasync, list);
+		list_del_init(&fasync->list);
+		spin_unlock_irq(&snd_fasync_lock);
+		if (fasync->on)
+			kill_fasync(&fasync->fasync, fasync->signal, fasync->poll);
+		spin_lock_irq(&snd_fasync_lock);
+	}
+	spin_unlock_irq(&snd_fasync_lock);
+}
+
+static DECLARE_WORK(snd_fasync_work, snd_fasync_work_fn);
+
+int snd_fasync_helper(int fd, struct file *file, int on,
+		      struct snd_fasync **fasyncp)
+{
+	struct snd_fasync *fasync = NULL;
+
+	if (on) {
+		fasync = kzalloc(sizeof(*fasync), GFP_KERNEL);
+		if (!fasync)
+			return -ENOMEM;
+		INIT_LIST_HEAD(&fasync->list);
+	}
+
+	spin_lock_irq(&snd_fasync_lock);
+	if (*fasyncp) {
+		kfree(fasync);
+		fasync = *fasyncp;
+	} else {
+		if (!fasync) {
+			spin_unlock_irq(&snd_fasync_lock);
+			return 0;
+		}
+		*fasyncp = fasync;
+	}
+	fasync->on = on;
+	spin_unlock_irq(&snd_fasync_lock);
+	return fasync_helper(fd, file, on, &fasync->fasync);
+}
+EXPORT_SYMBOL_GPL(snd_fasync_helper);
+
+void snd_kill_fasync(struct snd_fasync *fasync, int signal, int poll)
+{
+	unsigned long flags;
+
+	if (!fasync || !fasync->on)
+		return;
+	spin_lock_irqsave(&snd_fasync_lock, flags);
+	fasync->signal = signal;
+	fasync->poll = poll;
+	list_move(&fasync->list, &snd_fasync_list);
+	schedule_work(&snd_fasync_work);
+	spin_unlock_irqrestore(&snd_fasync_lock, flags);
+}
+EXPORT_SYMBOL_GPL(snd_kill_fasync);
+
+void snd_fasync_free(struct snd_fasync *fasync)
+{
+	if (!fasync)
+		return;
+	fasync->on = 0;
+	flush_work(&snd_fasync_work);
+	kfree(fasync);
+}
+EXPORT_SYMBOL_GPL(snd_fasync_free);