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

From: Greg Kroah-Hartman
Date: Tue Dec 15 2020 - 08:43:17 EST


On Tue, Dec 15, 2020 at 01:35:31PM +0000, Flavio Suligoi wrote:
> Hi Greg,
>
> > >
> > > switch (chip) {
> > > case CHIP_ID_F81865:
> > > + chip_name = "F81865";
> > > + break;
> > > case CHIP_ID_F81866:
> > > + chip_name = "F81866";
> > > + break;
> > > case CHIP_ID_F81966:
> > > + chip_name = "F81966";
> > > + break;
> > > case CHIP_ID_F81216AD:
> > > + chip_name = "F81216AD";
> > > + break;
> > > case CHIP_ID_F81216H:
> > > + 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?

thanks,

greg k-h