On Sat, Mar 11, 2023 at 05:00:23AM -0800, Sumitra Sharma wrote: > Hi Dan, > > The description in TODO is difficult to understand. I would appreciae if > you could help me understand it more in a step-by-step simplified means. > > "This configuration needs to be moved to sysfs instead of being done through > + IOCTL. Goind forward, we need to port userspace tools to use sysfs instead > + of IOCTL and then we would delete IOCTL." > This driver comes with a user space program to control it. Your patch breaks that program. Someone could find the program and change it to use a u32 instead of a u16 but the old version would still be broken so users would be confused. Generally, in the kernel we try to avoid doing configuration through ioctls these days but instead prefer to use sysfs. Now the driver uses a pi433_tx_cfg struct which is the same for both user space and kernel space. What we do is create a different one which is private to the kernel. Then in pi433_ioctl() we copy the user space struct and convert it to a kernel space struct (new format with a u32). Change the kernel to use the new struct every where except the pi433_ioctl. Then add some new sysfs files so that the user can control the bitrate without changing any of the rest of the struct. Update the user space tool to use sysfs instead of the ioctl. Then after everyone upgrades to the new version delete the ioctl. regards, dan carpenter
