summaryrefslogtreecommitdiff
path: root/include/sound/core.h
AgeCommit message (Collapse)Author
2024-08-09Merge branch 'topic/control-lookup-rwlock' into for-nextTakashi Iwai
Pull control lookup optimization changes. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-08-09ALSA: control: Optimize locking for look-upTakashi Iwai
For a fast look-up of a control element via either numid or name matching (enabled via CONFIG_SND_CTL_FAST_LOOKUP), a locking isn't needed at all thanks to Xarray. OTOH, the locking is still needed for a slow linked-list traversal, and that's rather a rare case. In this patch, we reduce the use of locking at snd_ctl_find_*() API functions, and switch from controls_rwsem to controls_rwlock for avoiding unnecessary lock inversions. This also resulted in a nice cleanup, as *_unlocked() version of snd_ctl_find_*() APIs can be dropped. snd_ctl_find_id_mixer_unlocked() is still left just as an alias of snd_ctl_find_id_mixer(), since soc-card.c has a wrapper and there are several users. Once after converting there, we can remove it later. Signed-off-by: Takashi Iwai <tiwai@suse.de> Link: https://patch.msgid.link/20240809104234.8488-3-tiwai@suse.de
2024-08-09ALSA: control: Rename ctl_files_rwlock to controls_rwlockTakashi Iwai
We'll re-use the existing rwlock for the protection of control list lookup, too, and now rename it to a more generic name. This is a preliminary change, only the rename of the struct field here, no functional changes. Signed-off-by: Takashi Iwai <tiwai@suse.de> Link: https://patch.msgid.link/20240809104234.8488-2-tiwai@suse.de
2024-08-08ALSA: core: Drop snd_print stuff and coTakashi Iwai
Now that all users of snd_print*() are gone, let's drop the functions completely. This also makes CONFIG_SND_VERBOSE_PRINTK redundant, and it's dropped, too. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Signed-off-by: Takashi Iwai <tiwai@suse.de> Link: https://patch.msgid.link/20240807133452.9424-55-tiwai@suse.de
2023-08-17ALSA: core: Drop snd_device_initialize()Takashi Iwai
Now all users of snd_device_intialize() are gone, let's drop it. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Signed-off-by: Curtis Malainey <cujomalainey@chromium.org> Tested-by: Curtis Malainey <cujomalainey@chromium.org> Link: https://lore.kernel.org/r/20230816160252.23396-10-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-08-17ALSA: control: Don't embed ctl_devTakashi Iwai
Embedding the ctl_dev in the snd_card object may result in UAF when the delayed kobj release is used; at the delayed kobj release, it still accesses the struct device itself while the card memory (that embeds the struct device) may be already gone. As a workaround, detach the struct device from the card object by allocating via the new snd_device_alloc() helper. The rest are just replacing ctl_dev access to the pointer. This is based on the fix Curtis posted initially. In this patch, the changes are split and use the new helper function instead. Link: https://lore.kernel.org/r/20230801171928.1460120-1-cujomalainey@chromium.org Reviewed-by: Jaroslav Kysela <perex@perex.cz> Signed-off-by: Curtis Malainey <cujomalainey@chromium.org> Tested-by: Curtis Malainey <cujomalainey@chromium.org> Link: https://lore.kernel.org/r/20230816160252.23396-3-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-08-17ALSA: core: Introduce snd_device_alloc()Takashi Iwai
Introduce a new helper, snd_device_alloc(), for allocating a struct device that is bound with the sound class. It's a replacement of snd_device_initialize(). Reviewed-by: Jaroslav Kysela <perex@perex.cz> Signed-off-by: Curtis Malainey <cujomalainey@chromium.org> Tested-by: Curtis Malainey <cujomalainey@chromium.org> Link: https://lore.kernel.org/r/20230816160252.23396-2-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-06-21sound: make all 'class' structures constIvan Orlov
Now that the driver core allows for struct class to be in read-only memory, making all 'class' structures to be declared at build time placing them into read-only memory, instead of having to be dynamically allocated at load time. Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Cc: Ivan Orlov <ivan.orlov0322@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Geoff Levand <geoff@infradead.org> Cc: Thierry Reding <treding@nvidia.com> Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de> Cc: alsa-devel@alsa-project.org Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20230620175633.641141-2-gregkh@linuxfoundation.org Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-05-08ALSA: core: update comment on snd_card.controls_rwsemOswald Buddenhagen
Since commit 5bbb1ab5bd ("control: use counting semaphore as write lock for ELEM_WRITE operation"), this has been locking the controls including their values, not just the list of controls. Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de> Link: https://lore.kernel.org/r/20230428095941.1706278-6-oswald.buddenhagen@gmx.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-02-08ALSA: core: Make snd_card_free() return voidUwe Kleine-König
The function returns 0 unconditionally. Make it return void instead and simplify all callers accordingly. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Jaroslav Kysela <perex@perex.cz> Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Acked-by: Geoff Levand <geoff@infradead.org> Acked-by: Thierry Reding <treding@nvidia.com> Link: https://lore.kernel.org/r/20230207191907.467756-4-u.kleine-koenig@pengutronix.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-02-08ALSA: core: Make snd_card_free_when_closed() return voidUwe Kleine-König
All callers from other files ignore the return value of this function. And it can only ever return a non-zero value if the parameter card is NULL. This cannot happen in snd_card_free() as card was dereferenced just before snd_card_free_when_closed() is called. So the error handling can be dropped there. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Jaroslav Kysela <perex@perex.cz> Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Acked-by: Geoff Levand <geoff@infradead.org> Acked-by: Thierry Reding <treding@nvidia.com> Link: https://lore.kernel.org/r/20230207191907.467756-3-u.kleine-koenig@pengutronix.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-02-08ALSA: core: Make snd_card_disconnect() return voidUwe Kleine-König
All callers from other files ignore the return value of this function. And it can only ever return a non-zero value if the parameter card is NULL. Move the check for card being NULL into snd_card_free_when_closed() to keep the previous behaviour. Note this isn't necessary for snd_card_disconnect_sync() because if card was NULL in there the dereference of card for dev_err() would oops the kernel. Replace this by an oops triggered by the dereference of card for spin_lock_irq(). Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Jaroslav Kysela <perex@perex.cz> Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Acked-by: Geoff Levand <geoff@infradead.org> Acked-by: Thierry Reding <treding@nvidia.com> Link: https://lore.kernel.org/r/20230207191907.467756-2-u.kleine-koenig@pengutronix.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-07-29ALSA: core: Add async signal helpersTakashi Iwai
Currently the call of kill_fasync() from an interrupt handler might lead to potential spin deadlocks, as spotted by syzkaller. Unfortunately, it's not so trivial to fix this lock chain as it's involved with the tasklist_lock that is touched in allover places. As a temporary workaround, this patch provides the way to defer the async signal notification in a work. The new helper functions, snd_fasync_helper() and snd_kill_faync() are replacements for fasync_helper() and kill_fasync(), respectively. In addition, snd_fasync_free() needs to be called at the destructor of the relevant file object. Link: https://lore.kernel.org/r/20220728125945.29533-2-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-06-15ALSA: control: Use xarray for faster lookupsTakashi Iwai
The control elements are managed in a single linked list and we traverse the whole list for matching each numid or ctl id per every inquiry of a control element. This is OK-ish for a small number of elements but obviously it doesn't scale. Especially the matching with the ctl id takes time because it checks each field of the snd_ctl_id element, e.g. the name string is matched with strcmp(). This patch adds the hash tables with Xarray for improving the lookup speed of a control element. There are two xarray tables added to the card; one for numid and another for ctl id. For the numid, we use the numid as the index, while for the ctl id, we calculate a hash key. The lookup is done via a single xa_load() execution. As long as the given control element is found on the Xarray table, that's fine, we can give back a quick lookup result. The problem is when no entry hits on the table, and for this case, we have a slight optimization. Namely, the driver checks whether we had a collision on Xarray table, and do a fallback search (linear lookup of the full entries) only if a hash key collision happened beforehand. So, in theory, the inquiry for a non-existing element might take still time even with this patch in a worst case, but this must be pretty rare. The feature is enabled via CONFIG_SND_CTL_FAST_LOOKUP, which is turned on as default. For simplicity, the option can be turned off only when CONFIG_EXPERT is set ("You are expert? Then you manage 1000 knobs"). Link: https://lore.kernel.org/r/20211028130027.18764-1-tiwai@suse.de Link: https://lore.kernel.org/r/20220609180504.775-1-tiwai@suse.de Link: https://lore.kernel.org/all/cover.1653813866.git.quic_rbankapu@quicinc.com/ Link: https://lore.kernel.org/r/20220610064537.18660-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-04-12ALSA: core: Add snd_card_free_on_error() helperTakashi Iwai
This is a small helper function to handle the error path more easily when an error happens during the probe for the device with the device-managed card. Since devres releases in the reverser order of the creations, usually snd_card_free() gets called at the last in the probe error path unless it already reached snd_card_register() calls. Due to this nature, when a driver expects the resource releases in card->private_free, this might be called too lately. As a workaround, one should call the probe like: static int __some_probe(...) { // do real probe.... } static int some_probe(...) { return snd_card_free_on_error(dev, __some_probe(dev, ...)); } so that the snd_card_free() is called explicitly at the beginning of the error path from the probe. This function will be used in the upcoming fixes to address the regressions by devres usages. Fixes: e8ad415b7a55 ("ALSA: core: Add managed card creation") Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20220412093141.8008-2-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-07-19ALSA: core: Add device-managed request_dma()Takashi Iwai
This patch adds a devres-supported helper for requesting an ISA DMA channel that will be automatically freed at the device unbinding. It'll be used by quite a few ISA sound drivers. Link: https://lore.kernel.org/r/20210715075941.23332-4-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-07-19ALSA: core: Add managed card creationTakashi Iwai
As a second step for preliminary to widen the devres usages among sound drivers, this patch adds a new ALSA core API function, snd_devm_card_new(), to create a snd_card object via devres. When a card object is created by this new function, snd_card_free() is called automatically and the card object resource gets released at the device unbinding time. However, the story isn't that simple. A caveat is that we have to call snd_card_free() at the very first of the whole resource release procedure, in order to assure that the all exposed devices on user-space are deleted and sync with processes accessing those devices before releasing resources. For achieving it, snd_card_register() adds a new devres action to trigger snd_card_free() automatically when the given card object is a "managed" one. Since usually snd_card_register() is the last step of the initialization, this should work in most cases. With all these tricks, some drivers can get rid of the whole driver remove callback code. About a bit of implementation details: the patch adds two new flags to snd_card object: managed and releasing. The former indicates that the object was created via snd_devm_card_new(), and the latter is used for avoiding the double-free of snd_card_free() calls. Both flags are fairly internal and likely uninteresting to normal users. Link: https://lore.kernel.org/r/20210715075941.23332-3-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-05-25ALSA: Drop superfluous argument from snd_power_wait()Takashi Iwai
The power_state argument of snd_power_wait() is superfluous, receiving only SNDRV_POWER_STATE_D0. Let's drop it in all callers for simplicity. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Acked-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210523090920.15345-6-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-05-25ALSA: control: Track in-flight control read/write/tlv accessesTakashi Iwai
Although the power state check is performed in various places (e.g. at the entrance of quite a few ioctls), there can be still some pending tasks that already went into the ioctl handler or other ops, and those may access the hardware even after the power state check. For example, kcontrol access ioctl paths that call info/get/put callbacks may update the hardware registers. If a system wants to assure the free from such hw access (like the case of PCI rescan feature we're going to implement in future), this situation must be avoided, and we have to sync such in-flight tasks finishing beforehand. For that purpose, this patch introduces a few new things in core code: - A refcount, power_ref, and a wait queue, power_ref_sleep, to the card object - A few new helpers, snd_power_ref(), snd_power_unref(), snd_power_ref_and_wait(), and snd_power_sync_ref() In the code paths that call kctl info/read/write/tlv ops, we check the power state with the newly introduced snd_power_ref_and_wait(). This function also takes the card.power_ref refcount for tracking this in-flight task. Once after the access finishes, snd_power_unref() is called to released the refcount in return. So the driver can sync via snd_power_sync_ref() assuring that all in-flight tasks have been finished. As of this patch, snd_power_sync_ref() is called only at snd_card_disconnect(), but it'll be used in other places in future. Note that atomic_t is used for power_ref intentionally instead of refcount_t. It's because of the design of refcount_t type; refcount_t cannot be zero-based, and it cannot do dec_and_test() call for multiple times, hence it's not suitable for our purpose. Also, this patch changes snd_power_wait() to accept only SNDRV_CTL_POWER_D0, which is the only value that makes sense. In later patch, the snd_power_wait() calls will be cleaned up. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Link: https://lore.kernel.org/r/20210523090920.15345-3-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-05-25ALSA: core: Use READ_ONCE() / WRITE_ONCE() for power state changeTakashi Iwai
We need proper barriers to handle the power state change of the card from different CPUs. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Link: https://lore.kernel.org/r/20210523090920.15345-2-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-04-08ALSA: control: Add memory consumption limit to user controlsTakashi Sakamoto
ALSA control interface allows users to add arbitrary control elements (called "user controls" or "user elements"), and its resource usage is limited just by the max number of control sets (currently 32). This limit, however, is quite loose: each allocation of control set may have 1028 elements, and each element may have up to 512 bytes (ILP32) or 1024 bytes (LP64) of value data. Moreover, each control set may contain the enum strings and TLV data, which can be up to 64kB and 128kB, respectively. Totally, the whole memory consumption may go over 38MB -- it's quite large, and we'd rather like to reduce the size. OTOH, there have been other requests even to increase the max number of user elements; e.g. ALSA firewire stack require the more user controls, hence we want to raise the bar, too. For satisfying both requirements, this patch changes the management of user controls: instead of setting the upper limit of the number of user controls, we check the actual memory allocation size and set the upper limit of the total allocation in bytes. As long as the memory consumption stays below the limit, more user controls are allowed than the current limit 32. At the same time, we set the lower limit (8MB) as default than the current theoretical limit, in order to lower the risk of DoS. As a compromise for lowering the default limit, now the actual memory limit is defined as a module option, 'max_user_ctl_alloc_size', so that user can increase/decrease the limit if really needed, too. Link: https://lore.kernel.org/r/s5htur3zl5e.wl-tiwai@suse.de Co-developed-by: Takashi Iwai <tiwai@suse.de> Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Tested-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Link: https://lore.kernel.org/r/20210408103149.40357-1-o-takashi@sakamocchi.jp Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-02-02ALSA: jack: implement software jack injection via debugfsHui Wang
This change adds audio jack injection feature through debugfs, with this feature, we could validate alsa userspace changes by injecting plugin or plugout events to the non-phantom audio jacks. With this change, the sound core will build the folders $debugfs_mount_dir/sound/cardN if SND_DEBUG and DEBUG_FS are enabled. And if users also enable the SND_JACK_INJECTION_DEBUG, the jack injection nodes will be built in the folder cardN like below: $tree $debugfs_mount_dir/sound $debugfs_mount_dir/sound ├── card0 │   ├── HDMI_DP_pcm_10_Jack │   │   ├── jackin_inject │   │   ├── kctl_id │   │   ├── mask_bits │   │   ├── status │   │   ├── sw_inject_enable │   │   └── type ... │   └── HDMI_DP_pcm_9_Jack │   ├── jackin_inject │   ├── kctl_id │   ├── mask_bits │   ├── status │   ├── sw_inject_enable │   └── type └── card1 ├── HDMI_DP_pcm_5_Jack │   ├── jackin_inject │   ├── kctl_id │   ├── mask_bits │   ├── status │   ├── sw_inject_enable │   └── type ... ├── Headphone_Jack │   ├── jackin_inject │   ├── kctl_id │   ├── mask_bits │   ├── status │   ├── sw_inject_enable │   └── type └── Headset_Mic_Jack ├── jackin_inject ├── kctl_id ├── mask_bits ├── status ├── sw_inject_enable └── type The nodes kctl_id, mask_bits, status and type are read-only, users could check jack or jack_kctl's information through them. The nodes sw_inject_enable and jackin_inject are directly used for injection. The sw_inject_enable is read-write, users could check if software injection is enabled or not on this jack, and users could echo 1 or 0 to enable or disable software injection on this jack. Once the injection is enabled, the jack will not change by hardware events anymore, once the injection is disabled, the jack will restore the last reported hardware events to the jack. The jackin_inject is write-only, if the injection is enabled, users could echo 1 or 0 to this node to inject plugin or plugout events to this jack. For the detailed usage information on these nodes, please refer to Documentation/sound/designs/jack-injection.rst. Reviewed-by: Takashi Iwai <tiwai@suse.de> Reviewed-by: Jaroslav Kysela <perex@perex.cz> Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com> Signed-off-by: Hui Wang <hui.wang@canonical.com> Link: https://lore.kernel.org/r/20210127085639.74954-2-hui.wang@canonical.com Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-10-26ALSA: fix kernel-doc markupsMauro Carvalho Chehab
Kernel-doc markups should use this format: identifier - description There is a common comment marked, instead, with kernel-doc notation. Some identifiers have different names between their prototypes and the kernel-doc markup. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Acked-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/535182d6f55d7a7de293dda9676df68f5f60afc6.1603469755.git.mchehab+huawei@kernel.org Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-03-23ALSA: core: Add snd_device_get_state() helperTakashi Iwai
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 <tiwai@suse.de>
2020-01-21ALSA: pcm: Set per-card upper limit of PCM buffer allocationsTakashi Iwai
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 <tiwai@suse.de>
2020-01-03ALSA: core: Treat snd_device_ops as constTakashi Iwai
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 <tiwai@suse.de>
2019-11-20ALSA: pcm: Add card sync_irq fieldTakashi Iwai
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 <tiwai@suse.de>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156Thomas Gleixner
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 <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-17ALSA: core: Don't refer to snd_cards array directlyTakashi Iwai
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 <tiwai@suse.de>
2019-02-06ALSA: info: Move card id proc creation into info.cTakashi Iwai
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 <perex@perex.cz> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-17ALSA: core: Assure control device to be registered at lastTakashi Iwai
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 <tzungbi@google.com> Tested-by: Tzung-Bi Shih <tzungbi@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-10-11ALSA: add snd_card_disconnect_sync()Takashi Iwai
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 <kuninori.morimoto.gx@renesas.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-08-30ALSA: Get rid of card power_lockTakashi Iwai
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 <tiwai@suse.de>
2017-08-04ALSA: control: obsolete user_ctl_lockTakashi Sakamoto
At a previous commit, concurrent requests for TLV data are maintained exclusively between read requests and write/command requests. TLV callback handlers in each driver has no risk from concurrent access for reference/change. In current implementation, 'struct snd_card' has a mutex to control concurrent accesses to user-defined element sets. This commit obsoletes it. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-05-17ALSA: Use IS_ENABLED() in common headersTakashi Iwai
Simplify the ifdef conditions with IS_ENABLED() macro in the common sound headers. No functional changes. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-11-15ALSA: core: Fix kernel-doc warningsTakashi Iwai
Several lines in sound/core.h get the kernel-doc warnings like ./include/sound/core.h:323: warning: No description found for parameter '...' where we use define like foo(x, args...) and "args" isn't mentioned in the comments. As an easy workaround, use simple __VA_ARGS__ for VLA in macros. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-12ALSA: hda_intel: add card number to irq descriptionHeiner Kallweit
Currently the info in /proc/interrupts doesn't allow to figure out which interrupt belongs to which card (HDMI, PCH, ..). Therefore add card details to the interrupt description. With the patch the info in /proc/interrupts looks like this: PCI-MSI 442368-edge snd_hda_intel:card1 PCI-MSI 49152-edge snd_hda_intel:card0 NOTE: this patch adds the new irq_descr field snd_card struct that is filled automatically at a card object creation. This can be used generically for other drivers as well. The changes for others will follow later -- tiwai Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-04-24ALSA: core: Remove superfluous exit calls for proc entriesTakashi Iwai
Since each proc entry is freed automatically by the parent, we don't have to take care of its life cycle any longer. This allows us to reduce a few more lines of codes. Acked-by: Jaroslav Kysela <perex@perex.cz> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-03-03ALSA: core: Re-add snd_device_disconnect()Takashi Iwai
Revive snd_device_disconnect() again so that it can be called from the individual driver. This time, HD-audio will need it. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-02-06ALSA: Add a helper to add a new attribute group to cardTakashi Iwai
For assigning sysfs entries for a card device from the driver, introduce a new helper function, snd_card_add_dev_attr(). In this way, we can avoid the possible race between the device registration and the sysfs addition / removal. The driver can pass a new attribute group to add freely. This has to be called before snd_card_register(). Currently, up to two extra groups can be added. More than that, it'll return an error. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-02-02ALSA: Drop snd_get_device() helperTakashi Iwai
Since the device is no longer hidden but embedded into each component, we no longer need snd_get_device(). Let's drop it and relevant codes. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-02-02ALSA: Simplify snd_device_register() variantsTakashi Iwai
Now that all callers have been replaced with snd_device_register_for_dev(), let's drop the obsolete device registration code and concentrate only on the code handling struct device directly. That said, - remove the old snd_device_register(), - rename snd_device_register_for_dev() with snd_device_register(), - drop superfluous arguments from snd_device_register(), - change snd_unregister_device() to pass the device pointer directly Reviewed-by: Jaroslav Kysela <perex@perex.cz> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-02-02ALSA: control: Embed struct deviceTakashi Iwai
This patch embeds a struct device for the control device into the card object and avoid the device creation at registration time. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-02-02ALSA: Add a helper to initialize deviceTakashi Iwai
Introduce a new helper function snd_device_initialize() to initialize the device object for sound devices. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-02-02ALSA: Allow to pass the device object to snd_register_device*()Takashi Iwai
This is a preliminary patch for the further work on embedding struct device into each sound device instance. It changes snd_register_device*() helpers to receive the device object directly for skipping creating a device there. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-06-18ALSA: control: Protect user controls against concurrent accessLars-Peter Clausen
The user-control put and get handlers as well as the tlv do not protect against concurrent access from multiple threads. Since the state of the control is not updated atomically it is possible that either two write operations or a write and a read operation race against each other. Both can lead to arbitrary memory disclosure. This patch introduces a new lock that protects user-controls from concurrent access. Since applications typically access controls sequentially than in parallel a single lock per card should be fine. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Jaroslav Kysela <perex@perex.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-05-23ALSA: Remove deprecated snd_card_create()Takashi Iwai
Now all calls have been fixed, let's get rid of the old definition. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-03-01ALSA: core - Define snd_pci_quirk without CONFIG_PCIDylan Reid
The hda codecs all use this struct and, with an HDA platform driver, will be able to be built without PCI. Signed-off-by: Dylan Reid <dgreid@chromium.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-02-25ALSA: Clean up snd_device_*() codesTakashi Iwai
A few code cleanups and optimizations. In addition, drop snd_device_disconnect() that isn't used at all, and drop the return values from snd_device_free*(). Another slight difference by this change is that now the device state will become always SNDRV_DEV_REGISTERED no matter whether dev_register ops is present or not. It's for better consistency. There should be no impact for the current tree, as the state isn't checked. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-02-25ALSA: Use priority list for managing device listTakashi Iwai
Basically, the device type specifies the priority of the device to be registered / freed, too. However, the priority value isn't well utilized but only it's checked as a group. This results in inconsistent register and free order (where each of them should be in reversed direction). This patch simplifies the device list management code by simply inserting a list entry at creation time in an incremental order for the priority value. Since we can just follow the link for register, disconnect and free calls, we don't have to specify the group; so the whole enum definitions are also simplified as well. The visible change to outside is that the priorities of some object types are revisited. For example, now the SNDRV_DEV_LOWLEVEL object is registered before others (control, PCM, etc) and, in return, released after others. Similarly, SNDRV_DEV_CODEC is in a lower priority than SNDRV_DEV_BUS for ensuring the dependency. Also, the unused SNDRV_DEV_TOPLEVEL, SNDRV_DEV_LOWLEVEL_PRE and SNDRV_DEV_LOWLEVEL_NORMAL are removed as a cleanup. Signed-off-by: Takashi Iwai <tiwai@suse.de>