Hi, Jassi: On Wed, 2019-01-16 at 10:22 -0600, Jassi Brar wrote: > On Tue, Jan 15, 2019 at 11:07 PM CK Hu <ck...@mediatek.com> wrote: > > > > This patch supplies a new framework API, mbox_abort_channel(), and > > a new controller interface, abort_data(). > > > > For some client's application, it need to clean up the data in channel > > but keep the channel so it could send data to channel later. > > > > Signed-off-by: CK Hu <ck...@mediatek.com> > > --- > > drivers/mailbox/mailbox.c | 23 +++++++++++++++++++++++ > > include/linux/mailbox_client.h | 1 + > > include/linux/mailbox_controller.h | 4 ++++ > > 3 files changed, 28 insertions(+) > > > > diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c > > index c6a7d4582dc6..281647162c76 100644 > > --- a/drivers/mailbox/mailbox.c > > +++ b/drivers/mailbox/mailbox.c > > @@ -428,6 +428,29 @@ struct mbox_chan *mbox_request_channel_byname(struct > > mbox_client *cl, > > } > > EXPORT_SYMBOL_GPL(mbox_request_channel_byname); > > > > +/** > > + * mbox_abort_channel - The client abort all data in a mailbox > > + * channel by this call. > > + * @chan: The mailbox channel to be aborted. > > + */ > > +void mbox_abort_channel(struct mbox_chan *chan) > > +{ > > + unsigned long flags; > > + > > + if (!chan || !chan->cl) > > + return; > > + > > + if (chan->mbox->ops->abort_data) > > + chan->mbox->ops->abort_data(chan); > > + > > + /* The queued TX requests are simply aborted, no callbacks are made > > */ > > + spin_lock_irqsave(&chan->lock, flags); > > + chan->cl = NULL; > > + chan->active_req = NULL; > > + spin_unlock_irqrestore(&chan->lock, flags); > > +} > > > Why not just release and then request channel again ? > mbox_abort_channel() is just a copy of mbox_free_channel() and if the > abort can sleep, that is more reason to just do that.
The cursor may change position 300 times in one second, so I still concern the processing time. Request and free channel looks too heavy to do 300 times per second. Conceptually, I just want to clean up the channel rather than free and request it, so they are somewhat different. I say it may sleep because mbox_abort_channel() is a copy of mbox_free_channel(). I could change it to 'must not sleep' because Mediatek controller does not sleep in abort callback. Regards, CK