Re: [PATCH] usb:serial: Add Fintek F81532/534 driver

[One Thousand Gnomes]

O
> +static int f81534_set_normal_register(struct usb_device *dev, u16 reg, u8 data)
> +{
> +	size_t count = F81534_USB_MAX_RETRY;
> +	int status;
> +	u8 *tmp;
> +
> +	tmp = kmalloc(sizeof(u8), GFP_KERNEL);
> +	if (!tmp)
> +		return -ENOMEM;

You end up doing huge numbers of tiny allocation and frees in some of the
code paths. I think it would be better to allocate them at a higher level
as they are not that cheap on CPU time.

> +static int f81534_read_data(struct usb_serial *usbserial, u32 address,
> +				size_t size, unsigned char *buf)
> +{

Is a particularly good example - you do 4 mallocs plus two per byte of
data.

Alan