Subject: [PATCH] usb: gadget: atmel_usba: fix crash when no endpoint are specified

From: [email-masked] (Nicolas Ferre)
Date: Fri, 28 Feb 2014 15:35:42 +0100

On 27/02/2014 16:42, Alexandre Belloni :
> If no endpoints are present in the device tree, the kernel will cras hwith the

s/cras hwith/crash with/

> following error:
> 
> Unable to handle kernel paging request at virtual address 00101008
> [...]
> [<c0222ff4>] (composite_dev_prepare) from [<c022326c>] (composite_bind+0x5c/0x190)
> [<c022326c>] (composite_bind) from [<c021ff8c>] (udc_bind_to_driver+0x48/0xf0)
> [<c021ff8c>] (udc_bind_to_driver) from [<c02208e0>] (usb_gadget_probe_driver+0x7c/0xa0)
> [<c02208e0>] (usb_gadget_probe_driver) from [<c0008970>] (do_one_initcall+0x94/0x140)
> [<c0008970>] (do_one_initcall) from [<c04b4b50>] (kernel_init_freeable+0xec/0x1b4)
> [<c04b4b50>] (kernel_init_freeable) from [<c0376cc4>] (kernel_init+0x8/0xe4)
> [<c0376cc4>] (kernel_init) from [<c0009590>] (ret_from_fork+0x14/0x24)
> Code: e5950014 e1a04001 e5902008 e3a010d0 (e5922008)
> ---[ end trace 35c74bdd89b373d0 ]---
> Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
> 
> This checks for that case and returns an error, not allowing the driver to be
> loaded with no endpoints.
> 
> Signed-off-by: Alexandre Belloni <[email-masked]>
> ---
>  drivers/usb/gadget/atmel_usba_udc.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/usb/gadget/atmel_usba_udc.c b/drivers/usb/gadget/atmel_usba_udc.c
> index 52771d4c44bc..e3e0c8ff242e 100644
> --- a/drivers/usb/gadget/atmel_usba_udc.c
> +++ b/drivers/usb/gadget/atmel_usba_udc.c
> @@ -1914,6 +1914,12 @@ static struct usba_ep * atmel_udc_of_init(struct platform_device *pdev,
>  		i++;
>  	}
>  
> +	if (i == 0) {
> +		dev_err(&pdev->dev, "of_probe: no endpoint specified\n");
> +		ret = -EINVAL;
> +		goto err;
> +	}
> +

It is better for debugging when creating a DT for a new SoC. So, okay.

Acked-by: Nicolas Ferre <[email-masked]>

>  	return eps;
>  err:
>  	return ERR_PTR(ret);

-- 
Nicolas Ferre