Re: [PATCH v2] x86/early_printk: add MMIO-based UARTs

[Denis Mukhin]

Hi,

Thanks for taking a look!

On Monday, March 17th, 2025 at 12:58 AM, Ingo Molnar <mingo@xxxxxxxxxx> wrote:

>
>
>
> * Denis Mukhin via B4 Relay devnull+dmukhin.ford.com@xxxxxxxxxx wrote:
>
> > + if (!strncmp(s, "nocfg", 5))
> > + baudrate = 0;
> > + else {
> > + baudrate = simple_strtoul(s, &e, 0);
> > + if (baudrate == 0 || s == e)
> > + baudrate = DEFAULT_BAUD;
> > + }
>
>
> In standard kernel coding style we always balance curly braces and
> don't skip them in the single-statement case. Ie. the above should be:
>
> if (!strncmp(s, "nocfg", 5)) {
> baudrate = 0;
> } else {
>
> > + if (baudrate)
> > + early_serial_hw_init(115200 / baudrate);
>
>
> Hm, I think that division will go poorly if 'baudrate' ends up being 0
> in the 'nocfg' case ... ;-)

This patch has a guardrail:
  early_serial_hw_init(115200 / baudrate);
will not be called in case of baudrate is 0.

I can re-write code to avoid confusion.

>
> Thanks,
>
> Ingo

Thanks,
Denis