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From:   Dan Williams <dan.j.williams@intel.com>
Date:   Fri, 15 Oct 2021 13:16:34 -0700
Message-ID: <CAPcyv4hOyXdoDcVUu8+x=xQCTfQQbafWZwA_wqmHq57K5DpEBw@mail.gmail.com>
Subject: Re: [PATCH v3 03/10] cxl/pci: Fix NULL vs ERR_PTR confusion
To:     Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc:     linux-cxl@vger.kernel.org, stable <stable@vger.kernel.org>,
        Ira Weiny <ira.weiny@intel.com>,
        Linux PCI <linux-pci@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Christoph Hellwig <hch@lst.de>
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On Fri, Oct 15, 2021 at 9:16 AM Jonathan Cameron
<Jonathan.Cameron@huawei.com> wrote:
>
> On Sat, 9 Oct 2021 09:44:13 -0700
> Dan Williams <dan.j.williams@intel.com> wrote:
>
> > cxl_pci_map_regblock() may return an ERR_PTR(), but cxl_pci_setup_regs()
> > is only prepared for NULL as the error case.
> >
>
> What's the logic behind doing this rather than adjusting the call site to
> check for an error pointer?

Minimize the fix for the stable backport. In the later patches the
cxl_pci_map_regblock() => cxl_map_regblock() conversion goes from
returning a pointer to an error code.

> Either approach is fine as far as I'm concerned though so this is really
> just a request for a bit more info in this patch description.

I can include that note above to clarify.

>
> FWIW
>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Thanks.