kernel/linux.git/include/sound/core.h, branch linux-5.8.y

ALSA: core: Add snd_device_get_state() helper

2020-03-23T17:09:19+00:00

A new small helper to get the current state of the device registration for the given object. It'll be used for USB-audio driver to check the delayed device registrations. Link: https://lore.kernel.org/r/20200323170643.19181-1-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: pcm: Set per-card upper limit of PCM buffer allocations

2020-01-21T06:11:55+00:00

Currently, the available buffer allocation size for a PCM stream depends on the preallocated size; when a buffer has been preallocated, the max buffer size is set to that size, so that application won't re-allocate too much memory. OTOH, when no preallocation is done, each substream may allocate arbitrary size of buffers as long as snd_pcm_hardware.buffer_bytes_max allows -- which can be quite high, HD-audio sets 1GB there. It means that the system may consume a high amount of pages for PCM buffers, and they are pinned and never swapped out. This can lead to OOM easily. For avoiding such a situation, this patch adds the upper limit per card. Each snd_pcm_lib_malloc_pages() and _free_pages() calls are tracked and it will return an error if the total amount of buffers goes over the defined upper limit. The default value is set to 32MB, which should be really large enough for usual operations. If larger buffers are needed for any specific usage, it can be adjusted (also dynamically) via snd_pcm.max_alloc_per_card option. Setting zero there means no chceck is performed, and again, unlimited amount of buffers are allowed. Link: https://lore.kernel.org/r/20200120124423.11862-1-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: core: Treat snd_device_ops as const

2020-01-03T08:23:50+00:00

This is a preliminary patch to allow const for snd_device_ops definitions in each driver's code. The ops reference is read-only, hence it can be declared as const for further optimization. There should be no functional changes by this patch. Link: https://lore.kernel.org/r/20200103081714.9560-4-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: pcm: Add card sync_irq field

2019-11-20T18:39:54+00:00

Many PCI and other drivers performs snd_pcm_period_elapsed() simply in its interrupt handler, so the sync_stop operation is just to call synchronize_irq(). Instead of putting this call multiple times, introduce the common card->sync_irq field. When this field is set, PCM core performs synchronize_irq() for sync-stop operation. Each driver just needs to copy its local IRQ number to card->sync_irq, and that's all we need. Link: https://lore.kernel.org/r/20191117085308.23915-8-tiwai@suse.de Signed-off-by: Takashi Iwai

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman

ALSA: core: Don't refer to snd_cards array directly

2019-04-17T05:16:15+00:00

The snd_cards[] array holds the card pointers that have been currently registered, and it's exported for the external modules that may need to refer a card object. But accessing to this array can be racy against the driver probe or removal, as the card registration or free may happen concurrently. This patch gets rid of the direct access to snd_cards[] array and provides a helper function to give the card object from the index number with a refcount management. Then the caller can access to the given card object safely, and releases it via snd_card_unref(). While we're at it, add a proper comment to snd_card_unref() and make it an inlined function for type-safety, too. Signed-off-by: Takashi Iwai

ALSA: info: Move card id proc creation into info.c

2019-02-06T17:11:58+00:00

The creation of card's id proc file can be moved gracefully into info.c. Also, the assignment of card->proc_id is superfluous and can be dropped. So let's do it. Basically this is no functional change but code refactoring, but one potential behavior change is that now it returns properly the error code from snd_info_card_register(), which is a good thing (tm). Reviewed-by: Jaroslav Kysela Signed-off-by: Takashi Iwai

ALSA: core: Assure control device to be registered at last

2018-05-17T06:21:23+00:00

The commit 289ca025ee1d ("ALSA: Use priority list for managing device list") changed the way to register/disconnect/free devices via a single priority list. This helped to make behavior consistent, but it also changed a slight behavior change: namely, the control device is registered earlier than others, while it was supposed to be the very last one. I've put SNDRV_DEV_CONTROL in the current position as the release of ctl elements often conflict with the private ctl elements some PCM or other components may create, which often leads to a double-free. But, the order of register and disconnect should be indeed fixed as expected in the early days: the control device gets registered at last, and disconnected at first. This patch changes the priority list order to move SNDRV_DEV_CONTROL as the last guy to assure the register / disconnect order. Meanwhile, for keeping the messy resource release order, manually treat the control and lowlevel devices as last freed one. Additional note: The lowlevel device is the device where a card driver creates at probe. And, we still keep the release order control -> lowlevel, as there might be link from a control element back to a lowlevel object. Fixes: 289ca025ee1d ("ALSA: Use priority list for managing device list") Reported-by: Tzung-Bi Shih Tested-by: Tzung-Bi Shih Signed-off-by: Takashi Iwai

ALSA: add snd_card_disconnect_sync()

2017-10-11T13:06:10+00:00

In case of user unbind ALSA driver during playing back / capturing, each driver needs to stop and remove it correctly. One note here is that we can't cancel from remove function in such case, because unbind operation doesn't check return value from remove function. So, we *must* stop and remove in this case. For this purpose, we need to sync (= wait) until the all top-level operations are canceled at remove function. For example, snd_card_free() processes the disconnection procedure at first, then waits for the completion. That's how the hot-unplug works safely. It's implemented, at least, in the top-level driver removal. Now for the lower level driver, we need a similar strategy. Notify to the toplevel for hot-unplug (disconnect in ALSA), and sync with the stop operation, then continue the rest of its own remove procedure. This patch adds snd_card_disconnect_sync(), and driver can use it from remove function. Note: the "lower level" driver here refers to a middle layer driver (e.g. ASoC components) that can be unbound freely during operation. Most of legacy ALSA helper drivers don't have such a problem because they can't be unbound. Note#2: snd_card_disconnect_sync() merely calls snd_card_disconnect() and syncs with closing all pending files. It takes only the files opened by user-space into account, and doesn't care about object refcounts. (The latter is handled by snd_card_free() completion call, BTW.) Also, the function doesn't free resources by itself. Tested-by: Kuninori Morimoto Signed-off-by: Takashi Iwai

ALSA: Get rid of card power_lock

2017-08-30T18:44:29+00:00

Currently we're taking power_lock at each card component for assuring the power-up sequence, but it doesn't help anything in the implementation at the moment: it just serializes unnecessarily the callers, but it doesn't protect about the power state change itself. It used to have some usefulness in the early days where we managed the PM manually. But now the suspend/resume core procedure is beyond our hands, and power_lock lost its meaning. This patch drops the power_lock from allover the places. There shouldn't be any issues by this change, as it's no helper regarding the power state change. Rather we'll get better performance by removing the serialization; which is the only slight concern of any behavior change, but it can't be a showstopper, after all. Signed-off-by: Takashi Iwai