6e2acbfe59
The function meson_clk_pll_enable() can be invoked under the enable_lock
spinlock from the clk core logic, which risks a kernel panic during the
usleep_range() call:
BUG: scheduling while atomic: kworker/u4:2/36/0x00000002
Modules linked in: g_ffs usb_f_fs libcomposite
CPU: 1 PID: 36 Comm: kworker/u4:2 Not tainted 6.4.0-rc5 #273
Workqueue: events_unbound async_run_entry_fn
Call trace:
dump_backtrace+0x9c/0x128
show_stack+0x20/0x38
dump_stack_lvl+0x48/0x60
dump_stack+0x18/0x28
__schedule_bug+0x58/0x78
__schedule+0x828/0xa88
schedule+0x64/0xd8
schedule_hrtimeout_range_clock+0xd0/0x208
schedule_hrtimeout_range+0x1c/0x30
usleep_range_state+0x6c/0xa8
meson_clk_pll_enable+0x1f4/0x310
clk_core_enable+0x78/0x200
clk_core_enable+0x58/0x200
clk_core_enable+0x58/0x200
clk_core_enable+0x58/0x200
clk_enable+0x34/0x60
So it is required to use the udelay() function instead of usleep_range()
for the atomic context safety.
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.