[PATCH] staging: dgap: fix kernel oops on port open

[Dan Carpenter]

On Wed, Feb 26, 2014 at 08:41:38AM -0500, Mark Hounschell wrote:
> -static void dgap_sysfs_create(struct board_t *brd)
> +static int dgap_tty_register_ports(struct board_t *brd)
>  {
>  	struct channel_t *ch;
> -	int j = 0;
> +	int i;
> +
> +	brd->SerialPorts = kcalloc(brd->nasync, sizeof(*brd->SerialPorts),
> +					GFP_KERNEL);
> +	if (brd->SerialPorts == NULL) {
> +		pr_err("dgap: Cannot allocate serial port memory\n");

Don't add these error messages here.  kcalloc() already prints a much
better error message.

> +		return -ENOMEM;
> +	}
> +	for (i = 0; i < brd->nasync; i++)
> +		tty_port_init(&brd->SerialPorts[i]);
> +
> +	brd->PrinterPorts = kcalloc(brd->nasync, sizeof(*brd->PrinterPorts),
> +					GFP_KERNEL);
> +	if (brd->PrinterPorts == NULL) {
> +		pr_err("dgap: Cannot allocate printer port memory\n");

kfree(brd->SerialPorts);

> +		return -ENOMEM;
> +	}
> +	for (i = 0; i < brd->nasync; i++)
> +		tty_port_init(&brd->PrinterPorts[i]);
>  
>  	ch = brd->channels[0];
> -	for (j = 0; j < brd->nasync; j++, ch = brd->channels[j]) {
> +	for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
>  		struct device *classp;

Put a blank line after the declaration block.

> -		classp = tty_register_device(brd->SerialDriver, j,
> -						&(ch->ch_bd->pdev->dev));
> +
> +		classp = tty_port_register_device(&brd->SerialPorts[i],
> +				brd->SerialDriver, brd->firstminor + i, NULL);


The more traditional way to break up the long lines is:

		classp = tty_port_register_device(&brd->SerialPorts[i],
						  brd->SerialDriver,
						  brd->firstminor + i, NULL);
		dgap_create_tty_sysfs(&ch->ch_tun, classp);
		ch->ch_tun.un_sysfs = classp;

		classp = tty_port_register_device(&brd->PrinterPorts[i],
						  brd->PrintDriver,
						  brd->firstminor + i,
						  NULL);
		dgap_create_tty_sysfs(&ch->ch_pun, classp);
		ch->ch_pun.un_sysfs = classp;

(also i re-ordered the last two lines).

(also I wouldn't have sent this email at all if there hadn't been that
missing kfree()).

regards,
dan carpenter

> +
>  		ch->ch_tun.un_sysfs = classp;
>  		dgap_create_tty_sysfs(&ch->ch_tun, classp);
>  
> -		classp = tty_register_device(brd->PrintDriver, j,
> -						&(ch->ch_bd->pdev->dev));
> +		classp = tty_port_register_device(&brd->PrinterPorts[i],
> +				brd->PrintDriver, brd->firstminor + i, NULL);
> +
>  		ch->ch_pun.un_sysfs = classp;
>  		dgap_create_tty_sysfs(&ch->ch_pun, classp);
>  	}
>  	dgap_create_ports_sysfiles(brd);
> +
> +	return 0;