Re: [PATCH v8 09/12] media: mtk-vcodec: Get rid of mtk_smi_larb_get/put

[Dafna Hirschfeld]

On 30.09.21 05:28, Yong Wu wrote:
> Hi Dafna,
>
> Thanks very much for the review.
>
> On Wed, 2021-09-29 at 14:13 +0200, Dafna Hirschfeld wrote:
> > On 29.09.21 03:37, Yong Wu wrote:
> > > MediaTek IOMMU has already added the device_link between the
> > > consumer
> > > and smi-larb device. If the vcodec device call the
> > > pm_runtime_get_sync,
> > > the smi-larb's pm_runtime_get_sync also be called automatically.
> > >
> > > CC: Tiffany Lin <tiffany.lin@xxxxxxxxxxxx>
> > > CC: Irui Wang <irui.wang@xxxxxxxxxxxx>
> > > Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
> > > Reviewed-by: Evan Green <evgreen@xxxxxxxxxxxx>
> > > Acked-by: Tiffany Lin <tiffany.lin@xxxxxxxxxxxx>
> > > Reviewed-by: Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxxxxxx>
> > > ---
> > >    .../platform/mtk-vcodec/mtk_vcodec_dec_pm.c   | 37 +++-----------
> > > --
> > >    .../platform/mtk-vcodec/mtk_vcodec_drv.h      |  3 --
> > >    .../platform/mtk-vcodec/mtk_vcodec_enc.c      |  1 -
> > >    .../platform/mtk-vcodec/mtk_vcodec_enc_pm.c   | 44 +++-----------
> > > -----
> > >    4 files changed, 10 insertions(+), 75 deletions(-)
> > >
> > > diff --git a/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_pm.c
> > > b/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_pm.c
> > > index 6038db96f71c..d0bf9aa3b29d 100644
> > > --- a/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_pm.c
> > > +++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_pm.c
> > > @@ -8,14 +8,12 @@
> > >    #include <linux/of_address.h>
> > >    #include <linux/of_platform.h>
> > >    #include <linux/pm_runtime.h>
> > > -#include <soc/mediatek/smi.h>
> > >    
> > >    #include "mtk_vcodec_dec_pm.h"
> > >    #include "mtk_vcodec_util.h"
> > >    
> > >    int mtk_vcodec_init_dec_pm(struct mtk_vcodec_dev *mtkdev)
> > >    {
> > > -	struct device_node *node;
> > >    	struct platform_device *pdev;
> > >    	struct mtk_vcodec_pm *pm;
> > >    	struct mtk_vcodec_clk *dec_clk;
> > > @@ -26,18 +24,7 @@ int mtk_vcodec_init_dec_pm(struct mtk_vcodec_dev
> > > *mtkdev)
> > >    	pm = &mtkdev->pm;
> > >    	pm->mtkdev = mtkdev;
> > >    	dec_clk = &pm->vdec_clk;
> > > -	node = of_parse_phandle(pdev->dev.of_node, "mediatek,larb", 0);
> > > -	if (!node) {
> > > -		mtk_v4l2_err("of_parse_phandle mediatek,larb fail!");
> > > -		return -1;
> > > -	}
> > >    
> > > -	pdev = of_find_device_by_node(node);
> > > -	of_node_put(node);
> > > -	if (WARN_ON(!pdev)) {
> > > -		return -1;
> > > -	}
> > > -	pm->larbvdec = &pdev->dev;
> > >    	pdev = mtkdev->plat_dev;
> > >    	pm->dev = &pdev->dev;
> > >    
> > > @@ -47,14 +34,11 @@ int mtk_vcodec_init_dec_pm(struct
> > > mtk_vcodec_dev *mtkdev)
> > >    		dec_clk->clk_info = devm_kcalloc(&pdev->dev,
> > >    			dec_clk->clk_num, sizeof(*clk_info),
> > >    			GFP_KERNEL);
> > > -		if (!dec_clk->clk_info) {
> > > -			ret = -ENOMEM;
> > > -			goto put_device;
> > > -		}
> > > +		if (!dec_clk->clk_info)
> > > +			return -ENOMEM;
> > >    	} else {
> > >    		mtk_v4l2_err("Failed to get vdec clock count");
> > > -		ret = -EINVAL;
> > > -		goto put_device;
> > > +		return -EINVAL;
> > >    	}
> > >    
> > >    	for (i = 0; i < dec_clk->clk_num; i++) {
> > > @@ -63,29 +47,24 @@ int mtk_vcodec_init_dec_pm(struct
> > > mtk_vcodec_dev *mtkdev)
> > >    			"clock-names", i, &clk_info->clk_name);
> > >    		if (ret) {
> > >    			mtk_v4l2_err("Failed to get clock name id =
> > > %d", i);
> > > -			goto put_device;
> > > +			return ret;
> > >    		}
> > >    		clk_info->vcodec_clk = devm_clk_get(&pdev->dev,
> > >    			clk_info->clk_name);
> > >    		if (IS_ERR(clk_info->vcodec_clk)) {
> > >    			mtk_v4l2_err("devm_clk_get (%d)%s fail", i,
> > >    				clk_info->clk_name);
> > > -			ret = PTR_ERR(clk_info->vcodec_clk);
> > > -			goto put_device;
> > > +			return PTR_ERR(clk_info->vcodec_clk);
> > >    		}
> > >    	}
> > >    
> > >    	pm_runtime_enable(&pdev->dev);
> > >    	return 0;
> > > -put_device:
> > > -	put_device(pm->larbvdec);
> > > -	return ret;
> > >    }
> > >    
> > >    void mtk_vcodec_release_dec_pm(struct mtk_vcodec_dev *dev)
> > >    {
> > >    	pm_runtime_disable(dev->pm.dev);
> > > -	put_device(dev->pm.larbvdec);
> > >    }
> >
> > Now that functions only do  'pm_runtime_disable(dev->pm.dev);' so it
> > will be more
> > readable to remove the function mtk_vcodec_release_dec_pm
> > and replace with pm_runtime_disable(dev->pm.dev);
> > Same for the 'enc' equivalent.
>
> Make sense. But It may be not proper if using pm_runtime_disable
> as the symmetry with mtk_vcodec_init_dec_pm in the mtk_vcodec_probe.
>
> Maybe we should move pm_runtime_enable out from mtk_vcodec_init_dec_pm
> into mtk_vcodec_probe. I could do a new patch for this. Is this ok for
> you?

yes, there is also asymettry when calling pm_runtime* in general,
I see in the decoder it is called from mtk_vcodec_dec_pm.c
but in the encoder it is called from mtk_vcodec_enc.c,

I think all calls to pm_runtime* should be out of the *_pm.c files
since for example 'mtk_vcodec_dec_pw_on' also do just one call to
pm_runtime_resume_and_get so this function can also be removed.

thanks,
Dafna

> > Thanks,
> > Dafna
>
> [snip]
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