On Sun, Jan 16, 2022 at 07:46:20PM +0100, Christophe JAILLET wrote:
> ice_misc_intr() is an irq handler. It should not sleep.
>
> Use GFP_ATOMIC instead of GFP_KERNEL when allocating some memory.
>
> Fixes: 348048e724a0 ("ice: Implement iidc operations")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> ---
> I've never played a lot with irq handler. My understanding is that they
> should never sleep.
Hi Christophe
Threaded interrupt handlers are allowed to sleep. However, this
handler is not being used in such a way. So your are probably correct
about GFP_KERNEL vs GFP_ATOMIC.
> ---
> drivers/net/ethernet/intel/ice/ice_main.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
> index 30814435f779..65de01f3a504 100644
> --- a/drivers/net/ethernet/intel/ice/ice_main.c
> +++ b/drivers/net/ethernet/intel/ice/ice_main.c
> @@ -3018,7 +3018,7 @@ static irqreturn_t ice_misc_intr(int __always_unused irq, void *data)
> struct iidc_event *event;
>
> ena_mask &= ~ICE_AUX_CRIT_ERR;
> - event = kzalloc(sizeof(*event), GFP_KERNEL);
> + event = kzalloc(sizeof(*event), GFP_ATOMIC);
> if (event) {
> set_bit(IIDC_EVENT_CRIT_ERR, event->type);
> /* report the entire OICR value to AUX driver */
What happens next is interesting...
event->reg = oicr;
ice_send_event_to_aux(pf, event);
where:
void ice_send_event_to_aux(struct ice_pf *pf, struct iidc_event *event)
{
struct iidc_auxiliary_drv *iadrv;
if (!pf->adev)
return;
device_lock(&pf->adev->dev);
iadrv = ice_get_auxiliary_drv(pf);
if (iadrv && iadrv->event_handler)
iadrv->event_handler(pf, event);
device_unlock(&pf->adev->dev);
}
device_lock() takes a mutex, not something you should be doing in
atomic context.
So it looks to me, this handler really should be running in thread
context...
Andrew
