[PATCH v3] mmc: mxs: Initialize the spinlock prior to using it

[PATCH v3] mmc: mxs: Initialize the spinlock prior to using it

[Fabio Estevam]

From: Fabio Estevam <fabio.estevam@nxp.com>

An interrupt may occur right after devm_request_irq() is called and
prior to the spinlock initialization, leading to a kernel oops,
as the interrupt handler uses the spinlock.

In order to prevent this problem, move the spinlock initialization 
prior to requesting the interrupts.

Fixes: e4243f13d10e (mmc: mxs-mmc: add mmc host driver for i.MX23/28)
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: Marek Vasut <marex@denx.de>
---
Changes since v2:
- Add a Fixes tag as suggested by Stefan
Changes since v1:
- Make it a standalone patch instead of patch series
- Cc stable as suggested by Stefan

 drivers/mmc/host/mxs-mmc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/mxs-mmc.c b/drivers/mmc/host/mxs-mmc.c
index d839147..44ecebd 100644
--- a/drivers/mmc/host/mxs-mmc.c
+++ b/drivers/mmc/host/mxs-mmc.c
@@ -661,13 +661,13 @@ static int mxs_mmc_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, mmc);
 
+	spin_lock_init(&host->lock);
+
 	ret = devm_request_irq(&pdev->dev, irq_err, mxs_mmc_irq_handler, 0,
 			       dev_name(&pdev->dev), host);
 	if (ret)
 		goto out_free_dma;
 
-	spin_lock_init(&host->lock);
-
 	ret = mmc_add_host(mmc);
 	if (ret)
 		goto out_free_dma;
-- 
2.7.4

Re: [PATCH v3] mmc: mxs: Initialize the spinlock prior to using it

[Ulf Hansson]

On 5 November 2016 at 20:45, Fabio Estevam <festevam@gmail.com> wrote:
> From: Fabio Estevam <fabio.estevam@nxp.com>
>
> An interrupt may occur right after devm_request_irq() is called and
> prior to the spinlock initialization, leading to a kernel oops,
> as the interrupt handler uses the spinlock.
>
> In order to prevent this problem, move the spinlock initialization
> prior to requesting the interrupts.
>
> Fixes: e4243f13d10e (mmc: mxs-mmc: add mmc host driver for i.MX23/28)
> Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
> Reviewed-by: Marek Vasut <marex@denx.de>

Thanks, applied for fixes!

Kind regards
Uffe

> ---
> Changes since v2:
> - Add a Fixes tag as suggested by Stefan
> Changes since v1:
> - Make it a standalone patch instead of patch series
> - Cc stable as suggested by Stefan
>
>  drivers/mmc/host/mxs-mmc.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/mxs-mmc.c b/drivers/mmc/host/mxs-mmc.c
> index d839147..44ecebd 100644
> --- a/drivers/mmc/host/mxs-mmc.c
> +++ b/drivers/mmc/host/mxs-mmc.c
> @@ -661,13 +661,13 @@ static int mxs_mmc_probe(struct platform_device *pdev)
>
>         platform_set_drvdata(pdev, mmc);
>
> +       spin_lock_init(&host->lock);
> +
>         ret = devm_request_irq(&pdev->dev, irq_err, mxs_mmc_irq_handler, 0,
>                                dev_name(&pdev->dev), host);
>         if (ret)
>                 goto out_free_dma;
>
> -       spin_lock_init(&host->lock);
> -
>         ret = mmc_add_host(mmc);
>         if (ret)
>                 goto out_free_dma;
> --
> 2.7.4
>