Re: [alsa-devel][RESEND PATCH] mfd: wm8994: Fix NULL pointer exception on missing pdata

[Lee Jones]

On Fri, 07 Aug 2015, Inha Song wrote:

> If we use the dev_get_platdata, pdata can be NULL in DT environments.
> Actually, NULL pointer exception is occurs with error messages like this:
> 
> [    1.226583] Unable to handle kernel NULL pointer dereference at virtual address 00000044
> [    1.467910] [<c02f1e38>] (wm8994_irq_init) from [<c02f1bd4>] (wm8994_i2c_probe+0x684/0x858)
> [    1.476241] [<c02f1bd4>] (wm8994_i2c_probe) from [<c0371c78>] (i2c_device_probe+0x11c/0x17c)
> 
> In wm8994-core, we already checked whether platform data is NULL and set the
> wm8994->pdata to platform data if platform data is not NULL.
> So, we can use wm8994->pdata instead of platform data.
> 
> Signed-off-by: Inha Song <ideal.song@xxxxxxxxxxx>
> Acked-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/mfd/wm8994-irq.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Bit late in the day to apply this to -fixes, so I'll apply it for v4.3
instead.

Applied, thanks.

> diff --git a/drivers/mfd/wm8994-irq.c b/drivers/mfd/wm8994-irq.c
> index 55c380a..55c59d9 100644
> --- a/drivers/mfd/wm8994-irq.c
> +++ b/drivers/mfd/wm8994-irq.c
> @@ -193,7 +193,7 @@ int wm8994_irq_init(struct wm8994 *wm8994)
>  {
>  	int ret;
>  	unsigned long irqflags;
> -	struct wm8994_pdata *pdata = dev_get_platdata(wm8994->dev);
> +	struct wm8994_pdata *pdata = &wm8994->pdata;
>  
>  	if (!wm8994->irq) {
>  		dev_warn(wm8994->dev,

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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