On 23.08.23 22:37, Simon Arlott wrote: Hi, I am terribly sorry, but this has to be a hard NO. This patch has an unsurmountable problem. Reasons below.
The serial_core driver (ttySx) exposes its supported ioctl values as read-only sysfs attributes. Add read-write sysfs attributes "close_delay" and "closing_wait" to cdc-acm (ttyACMx) devices. These are the same as the
If the tty core does not export them as writable it presumably has reasons for that. We cannot circumvent those reasons in a particular driver unless there are very special circumstances that make the driver a special case. The correct way to deal with this issue would be a proposal to change the generic serial code. Even there I am sceptical because we would carry the code duplication forever. ioctl() is the way you set the parameters for a serial port in a Unix system. We have tools for that. Adding a second method is problematic. But that is not for me to decide. As far as CDC-ACM, however, is concerned, I must reject this patch, because it fundamentally does something that should not be done, definitely not at this layer. Sorry Oliver
Signed-off-by: Simon Arlott <simon@xxxxxxxxxxx>
Nacked-by: Oliver Neukum <oneukum@xxxxxxxx>
