Hi Andreas,
On 20-07-18 17:47, Andreas Kemnade wrote:
> The restart handler is executed during the shutdown phase which is
> atomic/irq-less. The i2c framework supports atomic transfers since
> commit 63b96983a5dd ("i2c: core: introduce callbacks for atomic
> transfers") to address this use case. Using i2c regmap in that
> situation is not allowed:
Nice catch. I had the same issue with a DA9062 device. I have oen minor
nit, pls see inline.
> [ 165.177465] [ BUG: Invalid wait context ]
> [ 165.181479] 5.8.0-rc3-00003-g0e9088558027-dirty #11 Not tainted
> [ 165.187400] -----------------------------
> [ 165.191410] systemd-shutdow/1 is trying to lock:
> [ 165.196030] d85b4438
> (rn5t618:170:(&rn5t618_regmap_config)->lock){+.+.}-{3:3}, at:
> regmap_update_bits_base+0x30/0x70
> [ 165.206573] other info that might help us debug this:
> [ 165.211625] context-{4:4}
> [ 165.214248] 2 locks held by systemd-shutdow/1:
> [ 165.218691] #0: c131c47c (system_transition_mutex){+.+.}-{3:3}, at:
> __do_sys_reboot+0x90/0x204
> [ 165.227405] #1: c131efb4 (rcu_read_lock){....}-{1:2}, at:
> __atomic_notifier_call_chain+0x0/0x118
> [ 165.236288] stack backtrace:
> [ 165.239174] CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted
> 5.8.0-rc3-00003-g0e9088558027-dirty #11
> [ 165.248220] Hardware name: Freescale i.MX6 SoloLite (Device Tree)
> [ 165.254330] [<c0112110>] (unwind_backtrace) from [<c010bfa0>]
> (show_stack+0x10/0x14)
> [ 165.262084] [<c010bfa0>] (show_stack) from [<c058093c>]
> (dump_stack+0xe8/0x120)
> [ 165.269407] [<c058093c>] (dump_stack) from [<c01835a4>]
> (__lock_acquire+0x81c/0x2ca0)
> [ 165.277246] [<c01835a4>] (__lock_acquire) from [<c0186344>]
> (lock_acquire+0xe4/0x490)
> [ 165.285090] [<c0186344>] (lock_acquire) from [<c0c98638>]
> (__mutex_lock+0x74/0x954)
> [ 165.292756] [<c0c98638>] (__mutex_lock) from [<c0c98f34>]
> (mutex_lock_nested+0x1c/0x24)
> [ 165.300769] [<c0c98f34>] (mutex_lock_nested) from [<c07593ec>]
> (regmap_update_bits_base+0x30/0x70)
> [ 165.309741] [<c07593ec>] (regmap_update_bits_base) from [<c076b838>]
> (rn5t618_trigger_poweroff_sequence+0x34/0x64)
> [ 165.320097] [<c076b838>] (rn5t618_trigger_poweroff_sequence) from
> [<c076b874>] (rn5t618_restart+0xc/0x2c)
> [ 165.329669] [<c076b874>] (rn5t618_restart) from [<c01514f8>]
> (notifier_call_chain+0x48/0x80)
> [ 165.338113] [<c01514f8>] (notifier_call_chain) from [<c01516a8>]
> (__atomic_notifier_call_chain+0x70/0x118)
> [ 165.347770] [<c01516a8>] (__atomic_notifier_call_chain) from [<c0151768>]
> (atomic_notifier_call_chain+0x18/0x20)
> [ 165.357949] [<c0151768>] (atomic_notifier_call_chain) from [<c010a828>]
> (machine_restart+0x68/0x80)
> [ 165.367001] [<c010a828>] (machine_restart) from [<c0153224>]
> (__do_sys_reboot+0x11c/0x204)
> [ 165.375272] [<c0153224>] (__do_sys_reboot) from [<c0100080>]
> (ret_fast_syscall+0x0/0x28)
> [ 165.383364] Exception stack(0xd80a5fa8 to 0xd80a5ff0)
> [ 165.388420] 5fa0: 00406948 00000000 fee1dead 28121969
> 01234567 73299b00
> [ 165.396602] 5fc0: 00406948 00000000 00000000 00000058 be91abc8 00000000
> be91ab60 004056f8
> [ 165.404781] 5fe0: 00000058 be91aabc b6ed4d45 b6e56746
>
> Signed-off-by: Andreas Kemnade <andr...@kemnade.info>
> ---
> drivers/mfd/rn5t618.c | 44 ++++++++++++++++++++++++++++++++-----------
> 1 file changed, 33 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/mfd/rn5t618.c b/drivers/mfd/rn5t618.c
> index 6b37dd479d71..2ef61b55cd4b 100644
> --- a/drivers/mfd/rn5t618.c
> +++ b/drivers/mfd/rn5t618.c
> @@ -81,7 +81,7 @@ static const struct regmap_irq_chip rc5t619_irq_chip = {
> .mask_invert = true,
> };
>
> -static struct rn5t618 *rn5t618_pm_power_off;
> +static struct i2c_client *rn5t618_pm_power_off;
> static struct notifier_block rn5t618_restart_handler;
>
> static int rn5t618_irq_init(struct rn5t618 *rn5t618)
> @@ -114,13 +114,37 @@ static int rn5t618_irq_init(struct rn5t618 *rn5t618)
>
> static void rn5t618_trigger_poweroff_sequence(bool repower)
> {
> + int ret;
> +
> /* disable automatic repower-on */
> - regmap_update_bits(rn5t618_pm_power_off->regmap, RN5T618_REPCNT,
> - RN5T618_REPCNT_REPWRON,
> - repower ? RN5T618_REPCNT_REPWRON : 0);
> - /* start power-off sequence */
I would keep both comments.
Regards,
Marco
