On Mon, 2013-03-25 at 13:11 +0200, Felipe Balbi wrote:
> On Mon, Mar 25, 2013 at 12:53:44PM +0200, Luciano Coelho wrote:
> > Spin locks and completions are expensive in hard IRQ context and cause
> > problems with RT kernels. In RT kernels, both spin locks and
> > completions can schedule(), so we can't use them in hard irq context.
> >
> > Move handling code into the irq thread function to avoid that.
> >
> > Reported-by: Gregoire Gentil <gregoire@xxxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Luciano Coelho <coelho@xxxxxx>
> > ---
> > drivers/net/wireless/ti/wlcore/main.c | 53 +++++++++++++--------------------
> > 1 file changed, 21 insertions(+), 32 deletions(-)
> >
> > diff --git a/drivers/net/wireless/ti/wlcore/main.c b/drivers/net/wireless/ti/wlcore/main.c
> > index 248daa9..c2730a7 100644
> > --- a/drivers/net/wireless/ti/wlcore/main.c
> > +++ b/drivers/net/wireless/ti/wlcore/main.c
> > @@ -651,6 +651,25 @@ static irqreturn_t wlcore_irq(int irq, void *cookie)
> > unsigned long flags;
> > struct wl1271 *wl = cookie;
> >
> > + /* complete the ELP completion */
> > + spin_lock_irqsave(&wl->wl_lock, flags);
> > + set_bit(WL1271_FLAG_IRQ_RUNNING, &wl->flags);
> > + if (wl->elp_compl) {
> > + complete(wl->elp_compl);
> > + wl->elp_compl = NULL;
> > + }
> > +
> > + if (test_bit(WL1271_FLAG_SUSPENDED, &wl->flags)) {
> > + /* don't enqueue a work right now. mark it as pending */
> > + set_bit(WL1271_FLAG_PENDING_WORK, &wl->flags);
> > + wl1271_debug(DEBUG_IRQ, "should not enqueue work");
> > + disable_irq_nosync(wl->irq);
> > + pm_wakeup_event(wl->dev, 0);
> > + spin_unlock_irqrestore(&wl->wl_lock, flags);
> > + return IRQ_HANDLED;
> > + }
> > + spin_unlock_irqrestore(&wl->wl_lock, flags);
>
> I still think _irqrestore() here is wrong, since it will reenable the
> IRQ line... other than that, it looks alright.
As we discussed earlier, it won't re-enable, since it was not enabled
when we saved. But, in any case, as we agreed, I'll send a separate
patch removing it. Don't want to mix two things in the same patch.
--
Luca.
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