Hi Greg, On Mon, Feb 20, 2017 at 10:48 PM, Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx> wrote: > Web: https://git.kernel.org/torvalds/c/bc88c10d7e6900916f5e1ba3829d66a9de92b633 > Commit: bc88c10d7e6900916f5e1ba3829d66a9de92b633 > Parent: f9af456a61ecfbef8233c5046a9e347c9b98ba05 > Refname: refs/heads/master > Author: Waiman Long <longman@xxxxxxxxxx> > AuthorDate: Wed Feb 8 14:46:48 2017 -0500 > Committer: Ingo Molnar <mingo@xxxxxxxxxx> > CommitDate: Fri Feb 10 09:09:49 2017 +0100 > > locking/spinlock/debug: Remove spinlock lockup detection code > > The current spinlock lockup detection code can sometimes produce false > positives because of the unfairness of the locking algorithm itself. > > So the lockup detection code is now removed. Instead, we are relying > on the NMI watchdog to detect potential lockup. We won't have lockup > detection if the watchdog isn't running. > > The commented-out read-write lock lockup detection code are also > removed. > > Signed-off-by: Waiman Long <longman@xxxxxxxxxx> > Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: Sasha Levin <sasha.levin@xxxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Link: http://lkml.kernel.org/r/1486583208-11038-1-git-send-email-longman@xxxxxxxxxx > Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Can you please backport this commit to v4.9.x and/or ltsi? It fixes the following issue in 4.9.40-ltsi on r8a7740/armadillo: BUG: spinlock lockup suspected on CPU#0, swapper/1 lock: lcdc0_device+0xa0/0x258, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 CPU: 0 PID: 1 Comm: swapper Not tainted 4.9.40-ltsi-armadillo-00939-gfc8b396897fd0712 #36 Hardware name: Generic R8A7740 (Flattened Device Tree) [<c010d068>] (unwind_backtrace) from [<c010ab54>] (show_stack+0x10/0x14) [<c010ab54>] (show_stack) from [<c014fe9c>] (do_raw_spin_lock+0xd4/0x118) [<c014fe9c>] (do_raw_spin_lock) from [<c0357000>] (dev_pm_get_subsys_data+0x2c/0x9c) [<c0357000>] (dev_pm_get_subsys_data) from [<c0360978>] (genpd_add_device+0x38/0x1b4) [<c0360978>] (genpd_add_device) from [<c0360b74>] (of_genpd_add_device+0x38/0x50) [<c0360b74>] (of_genpd_add_device) from [<c0818ef8>] (board_staging_register_device+0xb0/0xe8) [<c0818ef8>] (board_staging_register_device) from [<c0818f54>] (board_staging_register_devices+0x24/0x2c) [<c0818f54>] (board_staging_register_devices) from [<c0818f88>] (runtime_board_check+0x2c/0x40) [<c0818f88>] (runtime_board_check) from [<c01016dc>] (do_one_initcall+0xac/0x154) [<c01016dc>] (do_one_initcall) from [<c0800ce8>] (kernel_init_freeable+0x104/0x1c4) [<c0800ce8>] (kernel_init_freeable) from [<c0522150>] (kernel_init+0x8/0x10c) [<c0522150>] (kernel_init) from [<c0106db0>] (ret_from_fork+0x14/0x24) Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds