Hi,
On 24/05/13 19:23, David Daney wrote:
> From: David Daney <david.daney@xxxxxxxxxx>
>
> As noted by Wladislav Wiebe:
> $ halt
> ..
> Sent SIGKILL to all processes
> Requesting system halt
> [66.729373] System halted.
> [66.733244]
> [66.734761] =====================================
> [66.739473] [ BUG: lock held at task exit time! ]
> [66.744188] 3.8.7-0-sampleversion-fct #49 Tainted: G O
> [66.750202] -------------------------------------
> [66.754913] init/21479 is exiting with locks still held!
> [66.760234] 1 lock held by init/21479:
> [66.763990] #0: (reboot_mutex){+.+...}, at: [<ffffffff801776c8>] SyS_reboot+0xe0/0x218
> [66.772165]
> [66.772165] stack backtrace:
> [66.776532] Call Trace:
> [66.778992] [<ffffffff805780a8>] dump_stack+0x8/0x34
> [66.783972] [<ffffffff801618b0>] do_exit+0x610/0xa70
> [66.788948] [<ffffffff801777a8>] SyS_reboot+0x1c0/0x218
> [66.794186] [<ffffffff8013d6a4>] handle_sys64+0x44/0x64
>
> This is an alternative fix to the one sent by Wladislav. We kill the
> watchdog for each CPU and then spin in WAIT with interrupts disabled.
> This is the lowest power mode for the OCTEON. If we were to spin with
> interrupts enabled, we would get a continual stream of warning messages
> and backtraces from the lockup detector, so I chose to disable
> interrupts.
>
good alternative!
Thanks.
--
Wladislav Wiebe
> Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
> Cc: Maxim Uvarov <muvarov@xxxxxxxxx>
> Cc: Wladislav Wiebe <wladislav.kw@xxxxxxxxx>
> ---
> arch/mips/cavium-octeon/setup.c | 15 +++++++++------
> 1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/arch/mips/cavium-octeon/setup.c b/arch/mips/cavium-octeon/setup.c
> index b0baa29..01b1b3f 100644
> --- a/arch/mips/cavium-octeon/setup.c
> +++ b/arch/mips/cavium-octeon/setup.c
> @@ -428,13 +428,16 @@ static void octeon_restart(char *command)
> */
> static void octeon_kill_core(void *arg)
> {
> - mb();
> - if (octeon_is_simulation()) {
> - /* The simulator needs the watchdog to stop for dead cores */
> - cvmx_write_csr(CVMX_CIU_WDOGX(cvmx_get_core_num()), 0);
> + if (octeon_is_simulation())
> /* A break instruction causes the simulator stop a core */
> - asm volatile ("sync\nbreak");
> - }
> + asm volatile ("break" ::: "memory");
> +
> + local_irq_disable();
> + /* Disable watchdog on this core. */
> + cvmx_write_csr(CVMX_CIU_WDOGX(cvmx_get_core_num()), 0);
> + /* Spin in a low power mode. */
> + while (true)
> + asm volatile ("wait" ::: "memory");
> }
>
>
>
