Benjamin Bara 3473cf43b9 i2c: core: Run atomic i2c xfer when !preemptible ... commit aa49c90894 upstream. Since bae1d3a05a, i2c transfers are non-atomic if preemption is disabled. However, non-atomic i2c transfers require preemption (e.g. in wait_for_completion() while waiting for the DMA). panic() calls preempt_disable_notrace() before calling emergency_restart(). Therefore, if an i2c device is used for the restart, the xfer should be atomic. This avoids warnings like: [ 12.667612] WARNING: CPU: 1 PID: 1 at kernel/rcu/tree_plugin.h:318 rcu_note_context_switch+0x33c/0x6b0 [ 12.676926] Voluntary context switch within RCU read-side critical section! ... [ 12.742376] schedule_timeout from wait_for_completion_timeout+0x90/0x114 [ 12.749179] wait_for_completion_timeout from tegra_i2c_wait_completion+0x40/0x70 ... [ 12.994527] atomic_notifier_call_chain from machine_restart+0x34/0x58 [ 13.001050] machine_restart from panic+0x2a8/0x32c Use !preemptible() instead, which is basically the same check as pre-v5.2. Fixes: bae1d3a05a ("i2c: core: remove use of in_atomic()") Cc: stable@vger.kernel.org # v5.2+ Suggested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Acked-by: Wolfram Sang <wsa@kernel.org> Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Tested-by: Nishanth Menon <nm@ti.com> Signed-off-by: Benjamin Bara <benjamin.bara@skidata.com> Link: https://lore.kernel.org/r/20230327-tegra-pmic-reboot-v7-2-18699d5dcd76@skidata.com Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2023-11-28 17:20:05 +00:00
..
algos	i2c: algo: bit: allow getsda to be NULL	2023-01-23 23:15:49 +01:00
busses	i2c: sun6i-p2wi: Prevent potential division by zero	2023-11-28 17:19:46 +00:00
muxes	i2c: muxes: i2c-mux-gpmux: Use of_get_i2c_adapter_by_node()	2023-10-21 19:57:18 +02:00
i2c-atr.c	media: i2c: add I2C Address Translator (ATR) support	2023-07-14 13:11:44 +02:00
i2c-boardinfo.c
i2c-core-acpi.c	i2c: add fwnode APIs	2023-01-17 09:29:59 +01:00
i2c-core-base.c	i2c: fix memleak in i2c_new_client_device()	2023-11-28 17:19:46 +00:00
i2c-core-of.c	Char/Misc drivers for 6.4-rc1	2023-04-27 12:07:50 -07:00
i2c-core-slave.c
i2c-core-smbus.c
i2c-core.h	i2c: core: Run atomic i2c xfer when !preemptible	2023-11-28 17:20:05 +00:00
i2c-dev.c	i2c: dev: copy userspace array safely	2023-11-28 17:19:47 +00:00
i2c-mux.c	i2c: mux: Avoid potential false error message in i2c_mux_add_adapter	2023-09-25 08:22:02 +02:00
i2c-slave-eeprom.c	i2c: Convert drivers to new .probe() callback	2023-03-09 21:59:30 +01:00
i2c-slave-testunit.c	i2c: Convert drivers to new .probe() callback	2023-03-09 21:59:30 +01:00
i2c-smbus.c	i2c: Convert drivers to new .probe() callback	2023-03-09 21:59:30 +01:00
i2c-stub.c
Kconfig	i2c: Make I2C_ATR invisible	2023-09-13 10:56:00 +02:00
Makefile	media: i2c: add I2C Address Translator (ATR) support	2023-07-14 13:11:44 +02:00