Hi Dan,
On Mon, Mar 03, 2025 at 11:11:35AM +0300, Dan Carpenter wrote:
> [ This bug seems really ancient. But so far as I can see it really is
> super old. I'm not sure why it's only showing up now. -dan ]
>
> Hello Dmitry Torokhov,
>
> Commit 3d0f0fa0cb55 ("Input: atkbd - restore repeat rate when
> resuming") from Aug 4, 2006 (linux-next), leads to the following
> Smatch static checker warning:
>
> drivers/input/keyboard/atkbd.c:604 atkbd_set_repeat_rate()
> warn: sleeping in atomic context
>
> drivers/input/keyboard/atkbd.c
> 583 static int atkbd_set_repeat_rate(struct atkbd *atkbd)
> 584 {
> 585 const short period[32] =
> 586 { 33, 37, 42, 46, 50, 54, 58, 63, 67, 75, 83, 92, 100, 109, 116, 125,
> 587 133, 149, 167, 182, 200, 217, 232, 250, 270, 303, 333, 370, 400, 435, 470, 500 };
> 588 const short delay[4] =
> 589 { 250, 500, 750, 1000 };
> 590
> 591 struct input_dev *dev = atkbd->dev;
> 592 unsigned char param;
> 593 int i = 0, j = 0;
> 594
> 595 while (i < ARRAY_SIZE(period) - 1 && period[i] < dev->rep[REP_PERIOD])
> 596 i++;
> 597 dev->rep[REP_PERIOD] = period[i];
> 598
> 599 while (j < ARRAY_SIZE(delay) - 1 && delay[j] < dev->rep[REP_DELAY])
> 600 j++;
> 601 dev->rep[REP_DELAY] = delay[j];
> 602
> 603 param = i | (j << 5);
> --> 604 return ps2_command(&atkbd->ps2dev, ¶m, ATKBD_CMD_SETREP);
>
> This fucntion call takes a mutex.
>
> 605 }
>
> The call tree is:
>
> atkbd_reconnect() <- disables preempt
> -> atkbd_set_repeat_rate()
>
> In atkbd_reconnect() it's the atkbd_disable(atkbd) which takes a
> spinlock.
I think your tools are confused by the guard notation. atkbd_disable()
not only takes but also releases the spinlock.
Thanks.
--
Dmitry
