Le 16/01/2022 à 22:42, Andrew Lunn a écrit :
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
Ok, thanks for the explanation.
ice_misc_intr() is registered with devm_request_irq(), so it is a
handler that can't sleep.
I guess that more consideration should be taken into account than only:
s/devm_request_irq(handler)/devm_request_threaded_irq(NULL, handler)/
So I'll leave this one to people with the expected know-how.
If my s/GFP_KERNEL/GFP_ATOMIC/ makes enough sense as-is, that's fine for
me, but it looks that another solution is needed to fix the 2nd issue.
CJ
