Re: [PATCH 1/7] media: hantro: add support for reset lines

[Andrzej Pietrasiewicz]

Hi Dan, hi Jernej,

W dniu 23.11.2021 o 15:59, Dan Carpenter pisze:
> On Tue, Nov 23, 2021 at 12:09:03PM +0100, Andrzej Pietrasiewicz wrote:
> > > diff --git a/drivers/staging/media/hantro/hantro_drv.c b/drivers/staging/media/hantro/hantro_drv.c
> > > index ab2467998d29..8c3de31f51b3 100644
> > > --- a/drivers/staging/media/hantro/hantro_drv.c
> > > +++ b/drivers/staging/media/hantro/hantro_drv.c
> > > @@ -905,6 +905,10 @@ static int hantro_probe(struct platform_device *pdev)
> > >    			return PTR_ERR(vpu->clocks[0].clk);
> > >    	}
> > > +	vpu->resets = devm_reset_control_array_get(&pdev->dev, false, true);
> > > +	if (IS_ERR(vpu->resets))
> > > +		return PTR_ERR(vpu->resets);
> > > +
> > >    	num_bases = vpu->variant->num_regs ?: 1;
> > >    	vpu->reg_bases = devm_kcalloc(&pdev->dev, num_bases,
> > >    				      sizeof(*vpu->reg_bases), GFP_KERNEL);
> > > @@ -978,10 +982,16 @@ static int hantro_probe(struct platform_device *pdev)
> > >    	pm_runtime_use_autosuspend(vpu->dev);
> > >    	pm_runtime_enable(vpu->dev);
>          ^^^^^^^^^^^^^^^^^^^^^^^^^^^
> It looks like this is the pm stuff that we have to unwind on error
>
> > > +	ret = reset_control_deassert(vpu->resets);
> > > +	if (ret) {
> > > +		dev_err(&pdev->dev, "Failed to deassert resets\n");
> > > +		return ret;
>                  ^^^^^^^^^^
> So this return should be a goto undo_pm_stuff
>
>
> > > +	}
> > > +
> > >    	ret = clk_bulk_prepare(vpu->variant->num_clocks, vpu->clocks);
> > >    	if (ret) {
> > >    		dev_err(&pdev->dev, "Failed to prepare clocks\n");
> > > -		return ret;
>
> And this return should also have been a goto so it's a bug in the
> original code.

So we probably want a separate patch addressing that first, and then
the series proper on top of that.

Regards,

Andrzej

> > > +		goto err_rst_assert;
> >
> > Before your patch is applied if clk_bulk_prepare() fails, we
> > simply return on the spot. After the patch is applied not only
> > do you...
> >
> > >    	}
> > >    	ret = v4l2_device_register(&pdev->dev, &vpu->v4l2_dev);
> > > @@ -1037,6 +1047,8 @@ static int hantro_probe(struct platform_device *pdev)
> > >    	v4l2_device_unregister(&vpu->v4l2_dev);
> > >    err_clk_unprepare:
> > >    	clk_bulk_unprepare(vpu->variant->num_clocks, vpu->clocks);
> > > +err_rst_assert:
> > > +	reset_control_assert(vpu->resets);
> >
> > ...revert the effect of reset_control_deassert(), you also...
> >
> > >    	pm_runtime_dont_use_autosuspend(vpu->dev);
> > >    	pm_runtime_disable(vpu->dev);
> >
> > ... do pm_*() stuff. Is there any reason why this is needed?
>
> So, yes, it's needed, but you're correct to spot that it's not
> consistent.
>
> regards,
> dan carpenter