[PATCH] arm64: defconfig: Increase SERIAL_8250_NR_UARTS to 10

Francesco Dolcini francesco at dolcini.it
Fri Dec 1 12:09:29 PST 2023


On Fri, Dec 01, 2023 at 11:57:53AM -0800, Florian Fainelli wrote:
> +Francesco,
> 
> On 12/1/23 11:12, Heiko Stuebner wrote:
> > From: Heiko Stuebner <heiko.stuebner at cherry.de>
> > 
> > Boards using socs like the rk3588 can use up to 10 uarts, so the default
> > of 4 is way too low. Therefore increase the maximum number to 10.
Do you have an actual need of 10, e.g. an existing board with 10 uarts
enabled supported by the mainline kernel? Just thinking at the last arm64 SoC I
am working with it should be 12 if we use this as a metric.

> > SERIAL_8250_RUNTIME_UARTS on the other hand describes the number of uart
> > data structures to prepare before registering them. This option can stay
> > at its default value of 4 since for one it can be changed via a boot
> > parameter 8250.nr_uarts but also since
> > commit 9d86719f8769 ("serial: 8250: Allow using ports higher than SERIAL_8250_RUNTIME_UARTS")
> > 
> > the kernel can register uarts dynamically that are above the
> > SERIAL_8250_RUNTIME_UARTS threshold.
> > 
> > Signed-off-by: Heiko Stuebner <heiko.stuebner at cherry.de>
> 
> There is a competing patch set from Francesco being submitted as well:
> https://lore.kernel.org/all/20231201171544.1901-1-francesco@dolcini.it/
>
> looks like some coordination is necessary.

Yep, thanks Florian.

Heiko: should I include your needs in my patch? It looks like these are the
days of the 8250 uart, I sent my patch just one day before yours.

Francesco




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