On Tue, Mar 04, 2025 at 11:09:35PM -0800, Dmitry Torokhov wrote:
> 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.
Argh... Yeah. Sorry. I'll fix that. I guess the problem is that
Smatch is confused by the if statement in class_serio_pause_rx_destructor()
regards,
dan carpenter
