Re: [PATCH] crypto: mxs-dcp - Fix wait logic on chan threads

From: Herbert Xu
Date: Fri Sep 28 2018 - 01:10:23 EST


On Fri, Sep 21, 2018 at 06:03:18PM +0300, Leonard Crestez wrote:
> When compiling with CONFIG_DEBUG_ATOMIC_SLEEP=y the mxs-dcp driver
> prints warnings such as:
>
> WARNING: CPU: 0 PID: 120 at kernel/sched/core.c:7736 __might_sleep+0x98/0x9c
> do not call blocking ops when !TASK_RUNNING; state=1 set at [<8081978c>] dcp_chan_thread_sha+0x3c/0x2ec
>
> The problem is that blocking ops will manipulate current->state
> themselves so it is not allowed to call them between
> set_current_state(TASK_INTERRUPTIBLE) and schedule().
>
> Fix this by converting the per-chan mutex to a spinlock (it only
> protects tiny list ops anyway) and rearranging the wait logic so that
> callbacks are called current->state as TASK_RUNNING. Those callbacks
> will indeed call blocking ops themselves so this is required.
>
> Signed-off-by: Leonard Crestez <leonard.crestez@xxxxxxx>

Patch applied. Thanks.
--
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