Re: crash in mmc subsystem during suspend

[Daniel Drake <dsd@laptop.org>]

On Sat, 2009-11-21 at 12:31 +0000, Matt Fleming wrote:
> Fancy giving this patch a try? I think it's just a case of removing too
> many funcs in the error path.

Thanks!
Yes, I agree that looks like the culprit.
I applied something very similar to your patch and the crash went away.

The one additional change I made is in sdio_bus.c :

 void sdio_remove_func(struct sdio_func *func)
 {
-       if (sdio_func_present(func))
-               device_del(&func->dev);
+       if (!sdio_func_present(func))
+               return;
 
+       device_del(&func->dev);
        put_device(&func->dev);
 }

I think this is necessary because the error path will go mmc_sdio_remove
--> sdio_remove_func
Hence sdio_remove_func() will be called when sdio_add_func() was never
called beforehand, so there is no func->dev reference to drop.

Do you agree? I'm not certain about this one.

Thanks!
Daniel


> diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
> index cdb845b..cdec9c8 100644
> --- a/drivers/mmc/core/sdio.c
> +++ b/drivers/mmc/core/sdio.c
> @@ -516,7 +516,8 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr)
>  	 * The number of functions on the card is encoded inside
>  	 * the ocr.
>  	 */
> -	card->sdio_funcs = funcs = (ocr & 0x70000000) >> 28;
> +	funcs = (ocr & 0x70000000) >> 28;
> +	card->sdio_funcs = 0;
>  
>  	/*
>  	 * If needed, disconnect card detection pull-up resistor.
> @@ -528,7 +529,7 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr)
>  	/*
>  	 * Initialize (but don't add) all present functions.
>  	 */
> -	for (i = 0;i < funcs;i++) {
> +	for (i = 0;i < funcs;i++,card->sdio_funcs++) {
>  		err = sdio_init_func(host->card, i + 1);
>  		if (err)
>  			goto remove;