Re: [PATCH v4 1/2] clk: hisilicon: Use correct return value about hisi_reset_init()

From: Stephen Boyd
Date: Thu May 28 2020 - 23:58:20 EST


Quoting Tiezhu Yang (2020-05-28 19:03:54)
> On 05/29/2020 07:15 AM, Stephen Boyd wrote:
> > Quoting Tiezhu Yang (2020-05-27 19:27:42)
> >> On 05/28/2020 03:06 AM, Stephen Boyd wrote:
> >>> Quoting Tiezhu Yang (2020-05-27 07:39:21)
> >>>> The return value about hisi_reset_init() is not correct, fix it.
> >>>>
> >>>> Fixes: e9a2310fb689 ("reset: hisilicon: fix potential NULL pointer dereference")
> >>> hisi_reset_init() returns NULL on error in that commit. This patch
> >>> doesn't make sense.
> >> Hi Stephen,
> >>
> >> The initial aim of this patch is to use correct return value about
> >> hisi_reset_init(), maybe NULL is OK, but the return value in this
> >> patch is more accurate.
> > The implementation of hisi_reset_init() that I see is this:
> >
> >
> > struct hisi_reset_controller *rstc;
> >
> > rstc = devm_kmalloc(&pdev->dev, sizeof(*rstc), GFP_KERNEL);
> > if (!rstc)
> > return NULL;
> >
> > rstc->membase = devm_platform_ioremap_resource(pdev, 0);
> > if (IS_ERR(rstc->membase))
> > return NULL;
> >
> > spin_lock_init(&rstc->lock);
> > rstc->rcdev.owner = THIS_MODULE;
> > rstc->rcdev.ops = &hisi_reset_ops;
> > rstc->rcdev.of_node = pdev->dev.of_node;
> > rstc->rcdev.of_reset_n_cells = 2;
> > rstc->rcdev.of_xlate = hisi_reset_of_xlate;
> > reset_controller_register(&rstc->rcdev);
> >
> > return rstc;
> >
> > And that returns NULL on an error and a valid pointer on success.
> > Changing the code to check the return value of hisi_reset_init() for an
> > error pointer is simply wrong without updating hisi_reset_init() to
> > return an error pointer on error. Where is the patch that changes
> > hisi_reset_init() to return an error pointer?
>
> Hi Stephen,
>
> Do you mean the following changes?

Yes where is this change?