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

From: Ulf Hansson
Date: Mon Nov 24 2014 - 03:35:04 EST


On 20 November 2014 at 15:45, lautriv <lautriv@xxxxxxxxxxxx> wrote:
> From b0509e27e33326e6dccd67d8ebe67e2bdb0cfdde Mon Sep 17 00:00:00 2001
> From: Helmut Stengele <lautriv@xxxxxxxxxxxx>
> Date: Thu, 20 Nov 2014 15:27:40 +0100
> Subject: [PATCH] mmc: wmt-sdmmc: fix unmatched release_mem_region
>
> Current code calls release_mem_region upon module unload
> without requesting the region first. This patch fixes it
> by moving to a devres-based ioremap implementation, which
> handles requesting and releasing memory region internally.
>
> This also makes the error/unload paths a bit simpler.
>
> Signed-off-by: Helmut Stengele <lautriv@xxxxxxxxxxxx>
> ---
>
> This is a corrected patch based on the one Alexey sent for me.
> I sent it already but since i'm not used to send something upstream
> it was an attached file and obviously rejected.
> Patch is tested on bare-metal ( wm8850 ) and works like suspected.
>
> drivers/mmc/host/wmt-sdmmc.c | 14 +++++---------
> 1 file changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/mmc/host/wmt-sdmmc.c b/drivers/mmc/host/wmt-sdmmc.c
> index 54181b4..bcaa0cc 100644
> --- a/drivers/mmc/host/wmt-sdmmc.c
> +++ b/drivers/mmc/host/wmt-sdmmc.c
> @@ -759,6 +759,7 @@ static int wmt_mci_probe(struct platform_device *pdev)
> const struct wmt_mci_caps *wmt_caps;
> int ret;
> int regular_irq, dma_irq;
> + struct resource *res;
>
> if (!of_id || !of_id->data) {
> dev_err(&pdev->dev, "Controller capabilities data missing\n");
> @@ -813,10 +814,11 @@ 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);
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + priv->sdmmc_base = devm_ioremap_resource(&pdev->dev, res);

You should check the return value from devm_ioremap_resource() with IS_ERR().

> if (!priv->sdmmc_base) {
> dev_err(&pdev->dev, "Failed to map IO space\n");

This print can be removed, devm_ioremap_resource() handles that.

> - ret = -ENOMEM;
> + ret = PTR_ERR(priv->sdmmc_base);
> goto fail2;
> }
>
> @@ -826,7 +828,7 @@ static int wmt_mci_probe(struct platform_device *pdev)
> ret = request_irq(regular_irq, wmt_mci_regular_isr, 0, "sdmmc", priv);
> if (ret) {
> dev_err(&pdev->dev, "Register regular IRQ fail\n");
> - goto fail3;
> + goto fail2;
> }
>
> ret = request_irq(dma_irq, wmt_mci_dma_isr, 0, "sdmmc", priv);
> @@ -869,8 +871,6 @@ fail5:
> free_irq(dma_irq, priv);
> fail4:
> free_irq(regular_irq, priv);
> -fail3:
> - iounmap(priv->sdmmc_base);
> fail2:
> mmc_free_host(mmc);
> fail1:
> @@ -881,7 +881,6 @@ static int wmt_mci_remove(struct platform_device *pdev)
> {
> struct mmc_host *mmc;
> struct wmt_mci_priv *priv;
> - struct resource *res;
> u32 reg_tmp;
>
> mmc = platform_get_drvdata(pdev);
> @@ -909,9 +908,6 @@ static int wmt_mci_remove(struct platform_device *pdev)
> clk_disable_unprepare(priv->clk_sdmmc);
> clk_put(priv->clk_sdmmc);
>
> - res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> - release_mem_region(res->start, resource_size(res));
> -
> mmc_free_host(mmc);
>
> dev_info(&pdev->dev, "WMT MCI device removed\n");
> --
> 2.1.3
>
>

Kind regards
Uffe
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