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| author | Takashi Iwai <tiwai@suse.de> | 2019-05-06 16:14:09 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2019-05-06 16:14:34 +0200 |
| commit | d81645510ce2a140816c4cb37c45b78d810ca63f (patch) | |
| tree | edd9464900904d22a23da362bb152669480c5d26 /Documentation/driver-api/usb/power-management.rst | |
| parent | 2854cd34fbab5f28a356d3667c26b7856a7b73e2 (diff) | |
| parent | 378d590c494551a68a824b939c711bb9a280e9ef (diff) | |
Merge tag 'asoc-v5.2' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Updates for v5.2
This is a pretty huge set of changes, it's been a pretty active release
all round but the big thing with this release is the Sound Open Firmware
changes from Intel, providing another DSP framework for use with the
DSPs in their SoCs. This one works with the firmware of the same name
which is free software (unlike the previous DSP firmwares and framework)
and there has been some interest in adoption by other systems already so
hopefully we will see adoption by other vendors in the future.
Other highlights include:
- Support for MCLK/sample rate ratio setting in the generic cards.
- Support for pin switches in the generic cards.
- A big set of improvements to the TLV320AIC32x4 drivers from Annaliese
McDermond.
- New drivers for Freescale audio mixers, several Intel machines,
several Mediatek machines, Meson G12A, Sound Open Firmware and
Spreadtrum compressed audio and DMA devices.
Diffstat (limited to 'Documentation/driver-api/usb/power-management.rst')
| -rw-r--r-- | Documentation/driver-api/usb/power-management.rst | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/Documentation/driver-api/usb/power-management.rst b/Documentation/driver-api/usb/power-management.rst index 79beb807996b..4a74cf6f2797 100644 --- a/Documentation/driver-api/usb/power-management.rst +++ b/Documentation/driver-api/usb/power-management.rst @@ -370,11 +370,15 @@ autosuspend the interface's device. When the usage counter is = 0 then the interface is considered to be idle, and the kernel may autosuspend the device. -Drivers need not be concerned about balancing changes to the usage -counter; the USB core will undo any remaining "get"s when a driver -is unbound from its interface. As a corollary, drivers must not call -any of the ``usb_autopm_*`` functions after their ``disconnect`` -routine has returned. +Drivers must be careful to balance their overall changes to the usage +counter. Unbalanced "get"s will remain in effect when a driver is +unbound from its interface, preventing the device from going into +runtime suspend should the interface be bound to a driver again. On +the other hand, drivers are allowed to achieve this balance by calling +the ``usb_autopm_*`` functions even after their ``disconnect`` routine +has returned -- say from within a work-queue routine -- provided they +retain an active reference to the interface (via ``usb_get_intf`` and +``usb_put_intf``). Drivers using the async routines are responsible for their own synchronization and mutual exclusion. |