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e8ad415b7a
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> |
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| .. | ||
| ac97 | ||
| aoa | ||
| arm | ||
| atmel | ||
| core | ||
| drivers | ||
| firewire | ||
| hda | ||
| i2c | ||
| isa | ||
| mips | ||
| oss | ||
| parisc | ||
| pci | ||
| pcmcia | ||
| ppc | ||
| sh | ||
| soc | ||
| sparc | ||
| spi | ||
| synth | ||
| usb | ||
| virtio | ||
| x86 | ||
| xen | ||
| ac97_bus.c | ||
| Kconfig | ||
| last.c | ||
| Makefile | ||
| sound_core.c | ||