Linux-ARM-Kernel Archive on lore.kernel.org
 help / color / Atom feed
From: CK Hu <ck.hu@mediatek.com>
To: Jassi Brar <jassisinghbrar@gmail.com>
Cc: srv_heupstream@mediatek.com,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Houlong Wei <houlong.wei@mediatek.com>,
	linux-mediatek@lists.infradead.org,
	Matthias Brugger <matthias.bgg@gmail.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 1/3] mailbox: Add ability for clients to abort data in channel
Date: Thu, 17 Jan 2019 16:00:32 +0800
Message-ID: <1547712032.5318.17.camel@mtksdaap41> (raw)
In-Reply-To: <CABb+yY0JfRbdVb_3wqxve1pYH0ZpFNrA2Kr6qovBruzhbeFRuw@mail.gmail.com>

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.hu@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.hu@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


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply index

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-16  5:04 [PATCH 0/3] Remove self-implemented queue of Mediatek cmdq CK Hu
2019-01-16  5:04 ` [PATCH 1/3] mailbox: Add ability for clients to abort data in channel CK Hu
2019-01-16 16:22   ` Jassi Brar
2019-01-17  8:00     ` CK Hu [this message]
2019-01-17 15:22       ` Jassi Brar
2019-01-16  5:04 ` [PATCH 2/3] mailbox: mediatek: Implement abort_data function CK Hu
2019-01-16  5:04 ` [PATCH 3/3] mailbox: mediatek: Remove busylist CK Hu
     [not found]   ` <40d519083fe94640a22181388bcbbb09@MTKMBS31N1.mediatek.inc>
2019-02-12  2:18     ` Dennis-YC Hsieh
2019-02-14 16:01       ` CK Hu
2019-02-14 16:12         ` Dennis-YC Hsieh

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1547712032.5318.17.camel@mtksdaap41 \
    --to=ck.hu@mediatek.com \
    --cc=houlong.wei@mediatek.com \
    --cc=jassisinghbrar@gmail.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mediatek@lists.infradead.org \
    --cc=matthias.bgg@gmail.com \
    --cc=srv_heupstream@mediatek.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-ARM-Kernel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/0 linux-arm-kernel/git/0.git
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/1 linux-arm-kernel/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-arm-kernel linux-arm-kernel/ https://lore.kernel.org/linux-arm-kernel \
		linux-arm-kernel@lists.infradead.org
	public-inbox-index linux-arm-kernel

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-arm-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git