On Thu, Dec 05, 2024 at 10:34:42AM +0100, Dave Penkler wrote:
> The USB_GPIB_SET_LINES command string used to be: "\nIBDC \n" but when
> we were merging this code into the upstream kernel we deleted the space
> character before the newline to make checkpatch happy. That turned
> out to be a mistake.
>
> The "\nIBDC" part of the string is a command that we pass to the
> firmware and the next character is a variable u8 value.
> It gets set in set_control_line().
>
> msg[leng - 2] = value ? (retval & ~line) : retval | line;
>
> where leng is the length of the command string.
>
> Imagine the parameter was supposed to be "8".
> With the pre-merge code the command string would be "\nIBDC8\n"
> With the post-merge code the command string became "\nIBD8\n"
>
> The firmware doesn't recognize "IBD8" as a valid command and rejects it.
>
> Putting a "." where the parameter is supposed to go fixes the driver
> and makes checkpatch happy. Same thing with the other define and
> the in-line assignment.
>
> Reported-by: Marcello Carla' <marcello.carla@xxxxxxx>
> Fixes: fce79512a96a ("staging: gpib: Add LPVO DIY USB GPIB driver")
> Co-developed-by: Marcello Carla' <marcello.carla@xxxxxxx>
> Signed-off-by: Marcello Carla' <marcello.carla@xxxxxxx>
> Signed-off-by: Dave Penkler <dpenkler@xxxxxxxxx>
> ---
Thank you!
Reviewed-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
regards,
dan carpenter
