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

Dan Carpenter
2021-11-23T15:00:47Z

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.

> > + 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