On Tue, Jan 12, 2021 at 05:13:16PM +0100, 'Greg Kroah-Hartman' wrote: > On Tue, Jan 12, 2021 at 03:43:22PM +0000, József Horváth wrote: > > On Tue, Jan 12, 2021 at 11:28:08AM +0100, 'Greg Kroah-Hartman' wrote: > > > On Tue, Jan 12, 2021 at 10:18:33AM +0000, Jozsef Horvath wrote: > > > > --- a/include/uapi/linux/serial_core.h > > > > +++ b/include/uapi/linux/serial_core.h > > > > @@ -279,4 +279,7 @@ > > > > /* Freescale LINFlexD UART */ > > > > #define PORT_LINFLEXUART 122 > > > > > > > > +/* Silicon Labs SI4455 */ > > > > +#define PORT_SI4455 123 > > > > > > What userspace tool is going to need this value? > > > > The PORT_SI4455 is defined for using as port type value in struct uart_port. > > I checked other serial drivers under drivers/tty/serial and the port types > > used by serial drivers are defined in two places: > > > > include/uapi/linux/serial_core.h > > include/uapi/linux/serial.h > > > > The port type is required by serial_core, and its value goes back to > > user space with TIOCGSERIAL ioctl call. > > What is it required for? Who uses this? > > > I can't set port type value to 0(PORT_UNKNOWN). > > Why not? In drivers/tty/serial/serial_core.c 1784: uart_port_activate(...) 1799: -> uart_startup(...) 260: -> uart_port_startup(...) 183: static int uart_port_startup(struct tty_struct *tty, struct uart_state *state, 184: int init_hw) ... 191: if (uport->type == PORT_UNKNOWN) 192: return 1; ... 221: retval = uport->ops->startup(uport); <--This is the reason. The drivers startup function is not get called if type==PORT_UNKNOWN ... > > > I think my drivers source is not the best place to defining PORT_SI4455, > > but I can't find better place then include/uapi/linux/serial_core.h > > > > Could you please help me where is the correct location for this definition? > > I ask as I am trying to figure out why we keep adding these ids, yet no > tool that i know of seems to actually use them. > > If you don't have a tool that needs to use a new id, then I would > recommend not adding it, right? This definition is not my requirement, but I would avoid collision with other drivers port type value. At this point as I understand your words, these definitions will be obsolete or optional soon and I can choose any value for drivers port type. Right? I would ask you about dev name (ttySSi). Is it okay? I didnt find any similar. > > thanks, > > greg k-h Üdvözlettel / Best regards: József Horváth
