linux-kernel - Re: [PATCH] mmc: wmt-sdmmc: fix unmatched release_mem

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Date:	Mon, 10 Nov 2014 21:17:03 +0100
From:	lautriv <lautriv@...dplug.net>
To:	Alexey Charkov <alchark@...il.com>
CC:	Fabio Estevam <festevam@...il.com>,
	Tony Prisk <linux@...sktech.co.nz>,
	Chris Ball <chris@...ntf.net>,
	Ulf Hansson <ulf.hansson@...aro.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linux-mmc@...r.kernel.org" <linux-mmc@...r.kernel.org>,
	linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] mmc: wmt-sdmmc: fix unmatched release_mem_region

On 11/10/2014 06:15 AM, Alexey Charkov wrote:
> 2014-11-10 1:18 GMT+03:00 lautriv <lautriv@...dplug.net>:
>> On 11/09/2014 10:55 PM, Fabio Estevam wrote:
>>> On Sun, Nov 9, 2014 at 7:12 PM, Alexey Charkov <alchark@...il.com> 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
>
Sorry for the delay, 8880's are used to crash a lot since
we have not enought information ;)
Attached a changed patch which will hopefully meet all needs.


View attachment "0001-mmc-vt8500-change-resource-mapping-to-devm_.patch" of type "text/x-patch" (2731 bytes)