On Wed, Nov 04, 2020 at 12:16:54PM +0530, Himadri Pandya wrote:
> The new usb_control_msg_recv() and usb_control_msg_send() nicely wraps
> usb_control_msg() with proper error check. Hence use the wrappers
> instead of calling usb_control_msg() directly.
>
> Signed-off-by: Himadri Pandya <himadrispandya@xxxxxxxxx>
> ---
> drivers/usb/serial/f81232.c | 88 ++++++++-----------------------------
> 1 file changed, 18 insertions(+), 70 deletions(-)
>
> diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
> index 0c7eacc630e0..78107feef8a8 100644
> --- a/drivers/usb/serial/f81232.c
> +++ b/drivers/usb/serial/f81232.c
> @@ -139,71 +139,36 @@ static int calc_baud_divisor(speed_t baudrate, speed_t clockrate)
> 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(*val),
> - USB_CTRL_GET_TIMEOUT);
> - if (status != sizeof(*val)) {
> + status = usb_control_msg_recv(dev, 0, F81232_REGISTER_REQUEST,
> + F81232_GET_REGISTER, reg, 0, val,
> + sizeof(*val), USB_CTRL_GET_TIMEOUT,
> + GFP_KERNEL);
This driver use tabs for indentation consistently so please stick to
that style. That should also amount to a smaller patch (and less noise
in the logs, e.g. for git blame).
> + if (status) {
> dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
>
> - if (status < 0)
> - status = usb_translate_errors(status);
> - else
> - status = -EIO;
> - } else {
> - status = 0;
> - *val = *tmp;
> + status = usb_translate_errors(status);
> }
>
> - kfree(tmp);
> return status;
> }
> @@ -866,32 +831,16 @@ static int f81534a_ctrl_set_register(struct usb_interface *intf, u16 reg,
> struct usb_device *dev = interface_to_usbdev(intf);
> int retry = F81534A_ACCESS_REG_RETRY;
> int status;
> - u8 *tmp;
> -
> - tmp = kmemdup(val, size, GFP_KERNEL);
> - if (!tmp)
> - return -ENOMEM;
>
> while (retry--) {
> - status = usb_control_msg(dev,
> - usb_sndctrlpipe(dev, 0),
> - F81232_REGISTER_REQUEST,
> - F81232_SET_REGISTER,
> - reg,
> - 0,
> - tmp,
> - size,
> - USB_CTRL_SET_TIMEOUT);
> - if (status < 0) {
> + status = usb_control_msg_send(dev, 0, F81232_REGISTER_REQUEST,
> + F81232_SET_REGISTER, reg, 0, val,
> + size, USB_CTRL_SET_TIMEOUT, GFP_KERNEL);
> + if (status) {
> + /* Retry on error or short transfers */
> status = usb_translate_errors(status);
> if (status == -EIO)
> continue;
So this now depends on the new helper returning an errno on short
transfers which gets mapped to -EIO by usb_translate_errors(). This
works currently (and with my suggested change to use -EREMOTEIO) but
could possibly lead to subtle regressions later.
I don't think we need to worry about it, but just wanted to highlight
the kind of impact these changes can have.
Note that this change also replaces a single memdup with a memdup+memcpy
for each iteration. But as this helper is used rarely (e.g. probe,
resume and disconnect), and hopefully the retries are exceptions, the
overhead could be acceptable.
> - } else if (status != size) {
> - /* Retry on short transfers */
> - status = -EIO;
> - continue;
> - } else {
> - status = 0;
> }
>
> break;
> @@ -902,7 +851,6 @@ static int f81534a_ctrl_set_register(struct usb_interface *intf, u16 reg,
> reg, status);
> }
>
> - kfree(tmp);
> return status;
> }
Johan
