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

From: Stephen Boyd
Date: Thu May 28 2020 - 19:15:59 EST


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?