lkml.org 
[lkml]   [2017]   [Nov]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] mailbox: txdone_method shouldn't always be reset
On Thu 16 Nov 22:47 PST 2017, Jassi Brar wrote:
> On 16 Nov 2017 23:12, "Bjorn Andersson" <bjorn.andersson@linaro.org> wrote:
> On Thu 16 Nov 09:06 PST 2017, Jassi Brar wrote:
> > diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
> > index 674b35f..95e480e 100644
> > --- a/drivers/mailbox/mailbox.c
> > +++ b/drivers/mailbox/mailbox.c
> > @@ -124,7 +124,8 @@ static enum hrtimer_restart txdone_hrtimer(struct
> > hrtimer *hrtimer)
> > for (i = 0; i < mbox->num_chans; i++) {
> > struct mbox_chan *chan = &mbox->chans[i];
> >
> > - if (chan->active_req && chan->cl) {
> > + if (chan->active_req && chan->cl &&
> > + chan->txdone_method == TXDONE_BY_POLL) {
>
> The hrtimer code will crash before reaching this point if the channel
> wasn't TXDONE_BY_POLL when it was created, so this part is not needed.
>
>
> We have one timer for all channels of a controller. While this channel may
> be run by ACK, some other might need to be POLLed. And we want to avoid
> polling this channel.
>

Oh, you're right.

But the fact that the timer function will poll channels that are
"upgraded" to ACK is a separate issue.

>
> > txdone = chan->mbox->ops->last_tx_done(chan);
> > if (txdone)
> > tx_tick(chan, 0);
> > @@ -418,7 +419,7 @@ void mbox_free_channel(struct mbox_chan *chan)
> > spin_lock_irqsave(&chan->lock, flags);
> > chan->cl = NULL;
> > chan->active_req = NULL;
> > - if (chan->txdone_method == TXDONE_BY_ACK)
> > + if (chan->txdone_method == TXDONE_BY_ACK &&
> chan->mbox->txdone_poll)
>
> This should be enough, but the logic here is not obvious. This relies on
> the fact that a mbox with txdone_poll would have been initialized as
> txdone = POLL and that txdone now being ACK would imply that it was
> "upgraded" in the request path.
>
> So at least this would have to be captured in a comment.
>
>
> Sure I'll add a comment.
>

Thanks

Regards,
Bjorn
\
 
 \ /
  Last update: 2017-11-17 17:18    [W:0.044 / U:1.468 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site