Re: [PATCH V8 04/10] USB: f81232: implement read IIR/MSR with endpoint

[Johan Hovold <johan@kernel.org>]

On Thu, Feb 26, 2015 at 06:02:10PM +0800, Peter Hung wrote:
> The interrupt endpoint will report current IIR. If we got IIR with MSR changed
> , We will do read MSR with interrupt_work worker to do f81232_read_msr()
> function.
> 
> Signed-off-by: Peter Hung <hpeter+linux_kernel@gmail.com>
> ---
>  drivers/usb/serial/f81232.c | 126 +++++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 118 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
> index cf5b902..46a81ef 100644
> --- a/drivers/usb/serial/f81232.c
> +++ b/drivers/usb/serial/f81232.c
> @@ -31,6 +31,13 @@ static const struct usb_device_id id_table[] = {
>  };
>  MODULE_DEVICE_TABLE(usb, id_table);
>  
> +/* USB Control EP parameter */
> +#define F81232_REGISTER_REQUEST	0xa0
> +#define F81232_GET_REGISTER	0xc0
> +
> +#define SERIAL_BASE_ADDRESS	0x0120
> +#define MODEM_STATUS_REGISTER	(0x06 + SERIAL_BASE_ADDRESS)

Could you indent the values using two tabs so the
INTERRUPT_ENABLE_REGISTER in a following patch will also fit?

> +
>  #define CONTROL_DTR			0x01
>  #define CONTROL_RTS			0x02
>  
> @@ -49,19 +56,112 @@ struct f81232_private {
>  	struct mutex lock;
>  	u8 line_control;
>  	u8 modem_status;
> +	struct work_struct interrupt_work;
> +	struct usb_serial_port *port;
>  };
>  
> +static int f81232_get_register(struct usb_serial_port *port, u16 reg, u8 *val)
> +{
> +	int status;
> +	u8 *tmp;
> +	struct usb_device *dev = port->serial->dev;
> +
> +	tmp = kmalloc(sizeof(*val), GFP_KERNEL);
> +	if (!tmp)
> +		return -ENOMEM;
> +
> +	status = usb_control_msg(dev,
> +				usb_rcvctrlpipe(dev, 0),
> +				F81232_REGISTER_REQUEST,
> +				F81232_GET_REGISTER,
> +				reg,
> +				0,
> +				tmp,
> +				sizeof(u8),

Please use sizeof(*val) here as well for consistency,

> +				USB_CTRL_GET_TIMEOUT);
> +	if (status != sizeof(*val)) {
> +		dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
> +
> +		if (status == 0)
> +			status = -EIO;
> +		else
> +			status = usb_translate_errors(status);

Could you rewrite this as

	if (status < 0)
		status = usb_translate_errors(status);
	else
		status = 0;

> +	} else {
> +		status = 0;
> +		*val = *tmp;
> +	}
> +
> +	kfree(tmp);
> +	return status;
> +}

Same comments apply to set_register in a follow up patch.

Looks good otherwise,
Johan