R: R: [PATCH v1] serial: 8250_fintek: Print Fintek chip name

From: Flavio Suligoi
Date: Tue Dec 15 2020 - 09:07:40 EST


Hi Greg,


> > > > + chip_name = "F81216H";
> > > > + break;
> > > > case CHIP_ID_F81216:
> > > > + chip_name = "F81216";
> > > > break;
> > > > default:
> > > > return -ENODEV;
> > > > }
> > > >
> > > > pdata->pid = chip;
> > > > +
> > > > + pr_info("%s%s%s Fintek %s\n",
> > > > + uart->port.dev ? dev_name(uart->port.dev) : "",
> > > > + uart->port.dev ? ": " : "",
> > > > + uart->port.name,
> > > > + chip_name);
> > >
> > > Drivers, if all goes well, should not print anything to the kernel
> log.
> > > This isn't ok.
> > >
> > > And even if it was, dev_info() would be the correct thing to do...
> >
> > Ok, too many information in the driver.
> >
> > But what do you think about the possibility to introduce
> > a new additional field, in "serial8250_config" structure,
> > such as "extra_name" or something like this:
> >
> > struct serial8250_config {
> > const char *name;
> > const char *extra_name;
> > unsigned short fifo_size;
> > unsigned short tx_loadsz;
> > unsigned char fcr;
> > unsigned char rxtrig_bytes[UART_FCR_R_TRIG_MAX_STATE];
> > unsigned int flags;
> > };
> >
> > In this way, if required, each driver can fill this
> > additional field, for example adding the name of
> > the particular uart chip or other useful info.
> >
> > As result, for example, the "uart_report_port" function output
> > could be something like this:
> >
> > 00:01: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A -
> Fintek F81216AD
> > 00:02: ttyS3 at I/O 0x2e8 (irq = 11, base_baud = 115200) is a 16550A -
> Fintek F81216AD
> >
> > where the "extra_name", if not empty, is printed
> > at the end of the line.
> > For practical space reasons, the "extra_name" length
> > can be limited to 16 chars.
>
> Why? What tool will use this, and why would userspace care about it?
>
> What problem are you trying to solve here?

I try to explain my requirement:

we produce some x86 boards with multistandard RS232/422/485 ports
and, to have this feature, in some of these boards, we use a
Fintek uart or superIO.
So this additional info "extra_name" can be useful for
a quick check if the serial ports are multistandard or not,
without any other investigations, but using only a simple command
like:

dmesg| grep ttyS

>
> thanks,
>
> greg k-h

Thanks and best regards,
Flavio