5447da5d61
Regulator drivers were modified to use asynchronous device probe. Since
then, the board .init_late hook fails to acquire a GPIO based fixed
regulator needed by an on-board voice MODEM device, and unregisters the
MODEM. That in turn triggers a so far not discovered bug of device
unregister function called for a device with no associated release() op.
serial8250 serial8250.1: incomplete constraints, dummy supplies not allowed
WARNING: CPU: 0 PID: 1 at drivers/base/core.c:2486 device_release+0x98/0xa8
Device 'serial8250.1' does not have a release() function, it is broken and
must be fixed. See Documentation/core-api/kobject.rst.
...
put_device from platform_device_put+0x1c/0x24
platform_device_put from ams_delta_init_late+0x4c/0x68
ams_delta_init_late from init_machine_late+0x1c/0x94
init_machine_late from do_one_initcall+0x60/0x1d4
As a consequence, ASoC CODEC driver is no longer able to control its
device over the voice MODEM's tty interface.
cx20442-codec: ASoC: error at soc_component_write_no_lock
on cx20442-codec for register: [0x00000000] -5
cx20442-codec: ASoC: error at snd_soc_component_update_bits_legacy
on cx20442-codec for register: [0x00000000] -5
cx20442-codec: ASoC: error at snd_soc_component_update_bits
on cx20442-codec for register: [0x00000000] -5
The regulator hangs of a GPIO pin controlled by basic-mmio-gpio driver.
Unlike most GPIO drivers, that driver doesn't probe for devices before
device_initcall, then GPIO pins under its control are not availabele to
majority of devices probed at that phase, including regulators. On the
other hand, serial8250 driver used by the MODEM device neither accepts via
platform data nor handles regulators, then the board file is not able to
teach that driver to return -EPROBE_DEFER when the regulator is not ready
so the failed probe is retried after late_initcall.
Resolve the issue by extending description of the MODEM device with a
dedicated power management domain. Acquire the regulator from the
domain's .activate hook and return -EPROBE_DEFER if the regulator is not
available. Having that under control, add the regulator device
description to the list of platform devices initialized from .init_machine
and drop the no longer needed custom .init_late hook.
v2: Trim down the warning for prettier git log output (Tony).
Fixes:
|
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.