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Manivannan Sadhasivam 45867d2ee4 watchdog: qcom: Avoid context switch in restart handler [ Upstream commit `7948fab26b` ] The use of msleep() in the restart handler will cause scheduler to induce a context switch which is not desirable. This generates below warning on SDX55 when WDT is the only available restart source: [ 39.800188] reboot: Restarting system [ 39.804115] ------------[ cut here ]------------ [ 39.807855] WARNING: CPU: 0 PID: 678 at kernel/rcu/tree_plugin.h:297 rcu_note_context_switch+0x190/0x764 [ 39.812538] Modules linked in: [ 39.821954] CPU: 0 PID: 678 Comm: reboot Not tainted 5.10.0-rc1-00063-g33a9990d1d66-dirty #47 [ 39.824854] Hardware name: Generic DT based system [ 39.833470] [<c0310fbc>] (unwind_backtrace) from [<c030c544>] (show_stack+0x10/0x14) [ 39.838154] [<c030c544>] (show_stack) from [<c0c218f0>] (dump_stack+0x8c/0xa0) [ 39.846049] [<c0c218f0>] (dump_stack) from [<c0322f80>] (__warn+0xd8/0xf0) [ 39.853058] [<c0322f80>] (__warn) from [<c0c1dc08>] (warn_slowpath_fmt+0x64/0xc8) [ 39.859925] [<c0c1dc08>] (warn_slowpath_fmt) from [<c038b6f4>] (rcu_note_context_switch+0x190/0x764) [ 39.867503] [<c038b6f4>] (rcu_note_context_switch) from [<c0c2aa3c>] (__schedule+0x84/0x640) [ 39.876685] [<c0c2aa3c>] (__schedule) from [<c0c2b050>] (schedule+0x58/0x10c) [ 39.885095] [<c0c2b050>] (schedule) from [<c0c2eed0>] (schedule_timeout+0x1e8/0x3d4) [ 39.892135] [<c0c2eed0>] (schedule_timeout) from [<c039ad40>] (msleep+0x2c/0x38) [ 39.899947] [<c039ad40>] (msleep) from [<c0a59d0c>] (qcom_wdt_restart+0xc4/0xcc) [ 39.907319] [<c0a59d0c>] (qcom_wdt_restart) from [<c0a58290>] (watchdog_restart_notifier+0x18/0x28) [ 39.914715] [<c0a58290>] (watchdog_restart_notifier) from [<c03468e0>] (atomic_notifier_call_chain+0x60/0x84) [ 39.923487] [<c03468e0>] (atomic_notifier_call_chain) from [<c030ae64>] (machine_restart+0x78/0x7c) [ 39.933551] [<c030ae64>] (machine_restart) from [<c0348048>] (__do_sys_reboot+0xdc/0x1e0) [ 39.942397] [<c0348048>] (__do_sys_reboot) from [<c0300060>] (ret_fast_syscall+0x0/0x54) [ 39.950721] Exception stack(0xc3e0bfa8 to 0xc3e0bff0) [ 39.958855] bfa0: 0001221c bed2fe24 fee1dead 28121969 01234567 00000000 [ 39.963832] bfc0: 0001221c bed2fe24 00000003 00000058 000225e0 00000000 00000000 00000000 [ 39.971985] bfe0: b6e62560 bed2fc84 00010fd8 b6e62580 [ 39.980124] ---[ end trace 3f578288bad866e4 ]--- Hence, replace msleep() with mdelay() to fix this issue. Fixes: `05e487d905` ("watchdog: qcom: register a restart notifier") Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20201207060005.21293-1-manivannan.sadhasivam@linaro.org Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		2020-12-30 11:53:58 +01:00
arch	powerpc/32s: Fix cleanup_cpu_mmu_context() compile bug	2020-12-30 11:53:58 +01:00
block	block-5.10-2020-12-05	2020-12-05 14:45:30 -08:00
certs	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
crypto	crypto: Kconfig - CRYPTO_MANAGER_EXTRA_TESTS requires the manager	2020-12-30 11:53:09 +01:00
Documentation	USB: UAS: introduce a quirk to set no_write_same	2020-12-21 13:30:08 +01:00
drivers	watchdog: qcom: Avoid context switch in restart handler	2020-12-30 11:53:58 +01:00
fs	NFS/pNFS: Fix a typo in ff_layout_resend_pnfs_read()	2020-12-30 11:53:57 +01:00
include	devlink: use _BITUL() macro instead of BIT() in the UAPI header	2020-12-30 11:53:58 +01:00
init	initramfs: fix clang build failure	2020-12-11 14:02:14 -08:00
ipc	ipc: adjust proc_ipc_sem_dointvec definition to match prototype	2020-09-05 12:14:29 -07:00
kernel	mm/gup: prevent gup_fast from racing with COW during fork	2020-12-30 11:53:54 +01:00
lib	selftest/fpu: avoid clang warning	2020-12-11 14:02:14 -08:00
LICENSES	LICENSES/deprecated: add Zlib license text	2020-09-16 14:33:49 +02:00
mm	mm: don't wake kswapd prematurely when watermark boosting is disabled	2020-12-30 11:53:55 +01:00
net	sunrpc: fix xs_read_xdr_buf for partial pages receive	2020-12-30 11:53:53 +01:00
samples	samples/bpf: Fix possible hang in xdpsock with multiple threads	2020-12-30 11:53:49 +01:00
scripts	checkpatch: fix unescaped left brace	2020-12-30 11:53:56 +01:00
security	selinux: fix inode_doinit_with_dentry() LABEL_INVALID error handling	2020-12-30 11:53:03 +01:00
sound	ASoC: wm_adsp: remove "ctl" from list on error in wm_adsp_create_control()	2020-12-30 11:53:50 +01:00
tools	perf test: Fix metric parsing test	2020-12-30 11:53:54 +01:00
usr	Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2020-08-07 13:29:39 -07:00
virt	kvm: x86/mmu: Support dirty logging for the TDP MMU	2020-10-23 03:42:13 -04:00
.clang-format	RDMA 5.10 pull request	2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore	Opt out of scripts/get_maintainer.pl	2019-05-16 10:53:40 -07:00
.gitattributes	.gitattributes: use 'dts' diff driver for dts files	2019-12-04 19:44:11 -08:00
.gitignore	.gitignore: docs: ignore sphinx_*/ directories	2020-09-10 10:44:31 -06:00
.mailmap	mailmap: add two more addresses of Uwe Kleine-König	2020-12-06 10:19:07 -08:00
COPYING	COPYING: state that all contributions really are covered by this file	2020-02-10 13:32:20 -08:00
CREDITS	MAINTAINERS: Move Jason Cooper to CREDITS	2020-11-30 10:20:34 +01:00
Kbuild	kbuild: rename hostprogs-y/always to hostprogs/always-y	2020-02-04 01:53:07 +09:00
Kconfig	kbuild: ensure full rebuild when the compiler is updated	2020-05-12 13:28:33 +09:00
MAINTAINERS	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2020-12-10 15:30:13 -08:00
Makefile	Linux 5.10.3	2020-12-26 16:02:46 +01:00
README	Drop all 00-INDEX files from Documentation/	2018-09-09 15:08:58 -06:00

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.