Re: [PATCH v2 13/14] soc: mediatek: cmdq: add wait no clear event function - Dennis-YC Hsieh

From: Dennis-YC Hsieh <dennis-yc.hsieh@mediatek.com>
To: CK Hu <ck.hu@mediatek.com>
Cc: Rob Herring <robh+dt@kernel.org>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Jassi Brar <jassisinghbrar@gmail.com>,
	<linux-kernel@vger.kernel.org>,
	<linux-mediatek@lists.infradead.org>,
	<devicetree@vger.kernel.org>, <wsd_upstream@mediatek.com>,
	Bibby Hsieh <bibby.hsieh@mediatek.com>,
	Houlong Wei <houlong.wei@mediatek.com>,
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v2 13/14] soc: mediatek: cmdq: add wait no clear event function
Date: Thu, 12 Dec 2019 09:42:55 +0800	[thread overview]
Message-ID: <1576114975.17653.16.camel@mtkswgap22> (raw)
In-Reply-To: <1576029887.19653.17.camel@mtksdaap41>

On Wed, 2019-12-11 at 10:04 +0800, CK Hu wrote:
> Hi, Dennis:
> 
> On Wed, 2019-11-27 at 09:58 +0800, Dennis YC Hsieh wrote:
> > Add wait no clear event function in cmdq helper functions to wait specific
> > event without clear to 0 after receive it.
> > 
> > Signed-off-by: Dennis YC Hsieh <dennis-yc.hsieh@mediatek.com>
> > ---
> >  drivers/soc/mediatek/mtk-cmdq-helper.c | 15 +++++++++++++++
> >  include/linux/soc/mediatek/mtk-cmdq.h  | 10 ++++++++++
> >  2 files changed, 25 insertions(+)
> > 
> > diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c
> > index 10a9b4481e58..6f270fadfb50 100644
> > --- a/drivers/soc/mediatek/mtk-cmdq-helper.c
> > +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
> > @@ -330,6 +330,21 @@ int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16 event)
> >  }
> >  EXPORT_SYMBOL(cmdq_pkt_wfe);
> >  
> > +int cmdq_pkt_wait_no_clear(struct cmdq_pkt *pkt, u16 event)
> > +{
> > +	struct cmdq_instruction inst = { {0} };
> > +
> > +	if (event >= CMDQ_MAX_EVENT)
> > +		return -EINVAL;
> > +
> > +	inst.op = CMDQ_CODE_WFE;
> > +	inst.value = CMDQ_WFE_WAIT | CMDQ_WFE_WAIT_VALUE;
> > +	inst.event = event;
> > +
> > +	return cmdq_pkt_append_command(pkt, inst);
> > +}
> > +EXPORT_SYMBOL(cmdq_pkt_wait_no_clear);
> 
> So the wait command has two version, one is wait and then clear event,
> another is wait and not clear event. The name of cmdq_pkt_wfe() is 'wait
> for event', so it's trivial that we think it does not clear event. I've
> three suggestion for this:
> 
> 1. Let cmdq_pkt_wfe() wait and not clear event, and
> cmdq_pkt_wfe_clear_event() wait and clear event.
> 
> or 
> 2. Let cmdq_pkt_wfe() has a parameter to indicate that clear event or
> not after wait.
> 
> or
> 3. Let cmdq_pkt_wfe() wait and not clear event, and not provide wait and
> clear event version. For DRM and MDP, I think both just need wait and
> not clear event.
> 
> Regards,
> CK
> 

ok, I will change cmdq_pkt_wfe wait and not clear, and expose another
cmdq_pkt_wfe_clear_event() api


Regards,
Dennis

> 
> > +
> >  int cmdq_pkt_clear_event(struct cmdq_pkt *pkt, u16 event)
> >  {
> >  	struct cmdq_instruction inst = { {0} };
> > diff --git a/include/linux/soc/mediatek/mtk-cmdq.h b/include/linux/soc/mediatek/mtk-cmdq.h
> > index d15d8c941992..40bc61ad8d31 100644
> > --- a/include/linux/soc/mediatek/mtk-cmdq.h
> > +++ b/include/linux/soc/mediatek/mtk-cmdq.h
> > @@ -149,6 +149,16 @@ int cmdq_pkt_write_s_value(struct cmdq_pkt *pkt, dma_addr_t addr,
> >   */
> >  int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16 event);
> >  
> > +/**
> > + * cmdq_pkt_wait_no_clear() - Append wait for event command to the CMDQ packet,
> > + *			      without update event to 0 after receive it.
> > + * @pkt:	the CMDQ packet
> > + * @event:	the desired event type to wait
> > + *
> > + * Return: 0 for success; else the error code is returned
> > + */
> > +int cmdq_pkt_wait_no_clear(struct cmdq_pkt *pkt, u16 event);
> > +
> >  /**
> >   * cmdq_pkt_clear_event() - append clear event command to the CMDQ packet
> >   * @pkt:	the CMDQ packet
> 
>