Re: [PATCH v1 2/2] media: platform: mtk-mdp3: fix error handling about components clock_on

From: moudy ho <moudy.ho@mediatek.com>
To: AngeloGioacchino Del Regno 
	<angelogioacchino.delregno@collabora.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: <linux-media@vger.kernel.org>,
	<linux-mediatek@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>,
	<Project_Global_Chrome_Upstream_Group@mediatek.com>
Subject: Re: [PATCH v1 2/2] media: platform: mtk-mdp3: fix error handling about components clock_on
Date: Mon, 3 Oct 2022 10:48:19 +0800	[thread overview]
Message-ID: <ff5ce171d32d70a939603ff700b44f140baab9c6.camel@mediatek.com> (raw)
In-Reply-To: <8afa9c8e-079e-6e50-a8d7-21e0b1698f76@collabora.com>

On Fri, 2022-09-30 at 14:12 +0200, AngeloGioacchino Del Regno wrote:
> Il 30/09/22 12:23, Moudy Ho ha scritto:
> > Add goto statement in mdp_comp_clock_on() to avoid error code not
> > being
> > propagated or returning positive values.
> > This change also performs a well-timed clock_off when an error
> > occurs, and
> > reduces unnecessary error logging in mdp_cmdq_send().
> > 
> > Fixes: 61890ccaefaf ("media: platform: mtk-mdp3: add MediaTek MDP3
> > driver")
> > Signed-off-by: Moudy Ho <moudy.ho@mediatek.com>
> > ---
> >   .../platform/mediatek/mdp3/mtk-mdp3-cmdq.c    |  4 +---
> >   .../platform/mediatek/mdp3/mtk-mdp3-comp.c    | 24
> > ++++++++++++++-----
> >   2 files changed, 19 insertions(+), 9 deletions(-)
> > 
> > diff --git a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-cmdq.c
> > b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-cmdq.c
> > index e194dec8050a..124c1b96e96b 100644
> > --- a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-cmdq.c
> > +++ b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-cmdq.c
> > @@ -433,10 +433,8 @@ int mdp_cmdq_send(struct mdp_dev *mdp, struct
> > mdp_cmdq_param *param)
> >   	cmd->mdp_ctx = param->mdp_ctx;
> >   
> >   	ret = mdp_comp_clocks_on(&mdp->pdev->dev, cmd->comps, cmd-
> > >num_comps);
> > -	if (ret) {
> > -		dev_err(dev, "comp %d failed to enable clock!\n", ret);
> > +	if (ret)
> >   		goto err_free_path;
> > -	}
> >   
> >   	dma_sync_single_for_device(mdp->cmdq_clt->chan->mbox->dev,
> >   				   cmd->pkt.pa_base, cmd-
> > >pkt.cmd_buf_size,
> > diff --git a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c
> > b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c
> > index d3eaf8884412..fe6a39315e88 100644
> > --- a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c
> > +++ b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c
> > @@ -699,12 +699,22 @@ int mdp_comp_clock_on(struct device *dev,
> > struct mdp_comp *comp)
> >   			dev_err(dev,
> >   				"Failed to enable clk %d. type:%d
> > id:%d\n",
> >   				i, comp->type, comp->id);
> > -			pm_runtime_put(comp->comp_dev);
> > -			return ret;
> > +			goto err_unwind;
> >   		}
> >   	}
> >   
> >   	return 0;
> > +
> > +err_unwind:
> 
> For this label to be clearer, I would rename it as `err_revert`, or
> `clocks_off`, or even simply `err`, as the `unwind` word may create
> some confusion here.
> 

Hi Angelo,

Thanks for the suggestion to rename to "err_revert" and make the flow
more readable.
I will correct it in the next version.

Regards,
Moudy

> > +	while (--i >= 0) {
> > +		if (IS_ERR_OR_NULL(comp->clks[i]))
> > +			continue;
> > +		clk_disable_unprepare(comp->clks[i]);
> > +	}
> > +	if (comp->comp_dev)
> > +		pm_runtime_put_sync(comp->comp_dev);
> > +
> > +	return ret;
> >   }
> >   
> >   void mdp_comp_clock_off(struct device *dev, struct mdp_comp
> > *comp)
> > @@ -723,11 +733,13 @@ void mdp_comp_clock_off(struct device *dev,
> > struct mdp_comp *comp)
> >   
> >   int mdp_comp_clocks_on(struct device *dev, struct mdp_comp
> > *comps, int num)
> >   {
> > -	int i;
> > +	int i, ret;
> >   
> > -	for (i = 0; i < num; i++)
> > -		if (mdp_comp_clock_on(dev, &comps[i]) != 0)
> > -			return ++i;
> > +	for (i = 0; i < num; i++) {
> > +		ret = mdp_comp_clock_on(dev, &comps[i]);
> > +		if (ret)
> > +			return ret;
> > +	}
> >   
> >   	return 0;
> >   }
> > 