Re: [PATCH] mmc: wmt-sdmmc: fix unmatched release_mem_region

From: Alexey Charkov
Date: Mon Nov 10 2014 - 00:15:26 EST


2014-11-10 1:18 GMT+03:00 lautriv <lautriv@xxxxxxxxxxxx>:
> On 11/09/2014 10:55 PM, Fabio Estevam wrote:
>>
>> On Sun, Nov 9, 2014 at 7:12 PM, Alexey Charkov <alchark@xxxxxxxxx> wrote:
>>
>>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> + if (!res) {
>>> + ret = -ENODEV;
>>> + goto fail1;
>>
>> You could save this NULL check...
>>
>>> + }
>>> mmc = mmc_alloc_host(sizeof(struct wmt_mci_priv), &pdev->dev);
>>> if (!mmc) {
>>> dev_err(&pdev->dev, "Failed to allocate mmc_host\n");
>>> @@ -813,7 +819,7 @@ static int wmt_mci_probe(struct platform_device
>>> *pdev)
>>> if (of_get_property(np, "cd-inverted", NULL))
>>> priv->cd_inverted = 1;
>>>
>>> - priv->sdmmc_base = of_iomap(np, 0);
>>
>> If you move ' res = platform_get_resource' right here as
>> devm_ioremap_resource() already does the NULL check.
>>
>>> + priv->sdmmc_base = devm_ioremap_resource(&pdev->dev, res);
>>> if (!priv->sdmmc_base) {
>>> dev_err(&pdev->dev, "Failed to map IO space\n");
>>> ret = -ENOMEM;
>
> This was the original intention but it would fall between the failX jumps, i
> discussed that with Alexey and we decided to change it with the cleanup to
> hold this patch small.

I think Fabio means something slightly different than what we
discussed. We haven't realized that the first thing
devm_ioremap_resource does is exactly that (!res) check, so we can
skip ours altogether.

Looking at the function code a bit closer, we should also make the
check look like "if (IS_ERR(priv->sdmmc_base)", kill the dev_err call
(as it's also done internally), and then just do "ret =
PTR_ERR(priv->sdmmc_base)" and jump to the label.

Thanks a lot,
Alexey
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