i2c: piix4: Request the SMBUS semaphore inside the mutex - net-next.git - net-next plumbings

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author	Ricardo Ribalda <ricardo.ribalda@gmail.com>	2017-02-02 20:15:16 +0100
committer	Wolfram Sang <wsa@the-dreams.de>	2017-02-09 17:13:01 +0100
commit	bbb27fc33d44e7b8d96369810654df4ee1837566 (patch)
tree	b769e165ad52c0021054f1a048b62bd7e4fbec47 /tools/testing/selftests/nsfs
parent	f43128c75202f29ee71aa83e6c320a911137c189 (diff)

i2c: piix4: Request the SMBUS semaphore inside the mutex

SMBSLVCNT must be protected with the piix4_mutex_sb800 in order to avoid multiple buses accessing to the semaphore at the same time. Fixes: 701dc207bf55 ("i2c: piix4: Avoid race conditions with IMC") Reported-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Diffstat (limited to 'tools/testing/selftests/nsfs')

0 files changed, 0 insertions, 0 deletions

with CONFIG_PREEMPT_RCU=y, which caused the code to try using workqueues before they were initialized, which did not go well. This commit therefore reworks RCU to permit synchronous grace periods to proceed during this mid-boot phase. This commit is therefore a fix to a regression introduced in v4.9, and is therefore being put forward post-merge-window in v4.10. This commit sets a flag from the existing rcu_scheduler_starting() function which causes all synchronous grace periods to take the expedited path. The expedited path now checks this flag, using the requesting task to drive the expedited grace period forward during the mid-boot phase. Finally, this flag is updated by a core_initcall() function named rcu_exp_runtime_mode(), which causes the runtime codepaths to be used. Note that this arrangement assumes that tasks are not sent POSIX signals (or anything similar) from the time that the first task is spawned through core_initcall() time. Fixes: 8b355e3bc140 ("rcu: Drive expedited grace periods from workqueue") Reported-by: "Zheng, Lv" <lv.zheng@intel.com> Reported-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Stan Kain <stan.kain@gmail.com> Tested-by: Ivan <waffolz@hotmail.com> Tested-by: Emanuel Castelo <emanuel.castelo@gmail.com> Tested-by: Bruno Pesavento <bpesavento@infinito.it> Tested-by: Borislav Petkov <bp@suse.de> Tested-by: Frederic Bezies <fredbezies@gmail.com> Cc: <stable@vger.kernel.org> # 4.9.0-

Diffstat (limited to 'tools/include')