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From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Tue, 5 Jun 2018 19:26:57 +0300
Message-ID: <CAHp75VdWhCDYt3jvii92g222WeHTvwX5e8Sthr0pknXvCgwHDA@mail.gmail.com>
Subject: Re: [PATCH] PCI: Clean up resource allocation in devm_of_pci_get_host_bridge_resources()
To:     Jan Kiszka <jan.kiszka@siemens.com>
Cc:     Bjorn Helgaas <bhelgaas@google.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-pci@vger.kernel.org,
        linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
        Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>,
        Jingoo Han <jingoohan1@gmail.com>,
        Joao Pinto <Joao.Pinto@synopsys.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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On Wed, May 16, 2018 at 3:31 PM, Jan Kiszka <jan.kiszka@siemens.com> wrote:
> Instead of first allocating and then freeing memory for struct resource
> in case we cannot parse a PCI resource from the device tree, work
> against a local struct and kmemdup it when we decide to go with it.
>

Bjorn, any comments on this?

> Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>  drivers/pci/of.c | 14 ++++++--------
>  1 file changed, 6 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/pci/of.c b/drivers/pci/of.c
> index b06585a1da75..fc0f906c5c25 100644
> --- a/drivers/pci/of.c
> +++ b/drivers/pci/of.c
> @@ -266,7 +266,7 @@ int devm_of_pci_get_host_bridge_resources(struct device *dev,
>                         struct list_head *resources, resource_size_t *io_base)
>  {
>         struct device_node *dev_node = dev->of_node;
> -       struct resource *res;
> +       struct resource *res, tmp_res;
>         struct resource *bus_range;
>         struct of_pci_range range;
>         struct of_pci_range_parser parser;
> @@ -320,18 +320,16 @@ int devm_of_pci_get_host_bridge_resources(struct device *dev,
>                 if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
>                         continue;
>
> -               res = devm_kzalloc(dev, sizeof(struct resource), GFP_KERNEL);
> +               err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
> +               if (err)
> +                       continue;
> +
> +               res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
>                 if (!res) {
>                         err = -ENOMEM;
>                         goto failed;
>                 }
>
> -               err = of_pci_range_to_resource(&range, dev_node, res);
> -               if (err) {
> -                       devm_kfree(dev, res);
> -                       continue;
> -               }
> -
>                 if (resource_type(res) == IORESOURCE_IO) {
>                         if (!io_base) {
>                                 dev_err(dev,
> --
> 2.13.6


-- 
With Best Regards,
Andy Shevchenko