Re: Re: [PATCH V2] serial: 8250_pnp: Support configurable clock frequency

[Huacai Chen <chenhuacai@xxxxxxxxx>]

Hi, Andy,

On Wed, Jul 14, 2021 at 4:58 PM Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
>
> On Wed, Jul 14, 2021 at 5:36 AM 陈华才 <chenhuacai@xxxxxxxxxxx> wrote:
>
> ...
>
> > &gt; &gt;  #include <linux kernel.h="">
> > &gt; &gt;  #include <linux serial_core.h="">
> > &gt; &gt;  #include <linux bitops.h="">
> > &gt; &gt; +#include <linux property.h="">
> > &gt;
> > &gt; Can you try to keep it ordered (to some extend), please?
> > Existing headers is not in order,
>
> That's why I added in the parentheses "to some extent".
>
> > should I sort them completely?
>
> Just put property.h before serial_core.h.
>
> ...
>
> > &gt; &gt;       uart.port.flags |= UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;
> > &gt; &gt;       if (pnp_irq_flags(dev, 0) &amp; IORESOURCE_IRQ_SHAREABLE)
> > &gt; &gt;               uart.port.flags |= UPF_SHARE_IRQ;
> > &gt; &gt; -     uart.port.uartclk = 1843200;
> > &gt; &gt; +     if (device_property_read_u32(&amp;dev-&gt;dev, "clock-frequency", &amp;uart.port.uartclk))
> > &gt; &gt; +             uart.port.uartclk = 1843200;
> > &gt; &gt;       uart.port.dev = &amp;dev-&gt;dev;
> > &gt;
> > &gt; You can avoid conditional completely by calling
> > &gt;
> > &gt;    device_property_read_u32(&amp;dev-&gt;dev, "clock-frequency", &amp;uart.port.uartclk);
> > I want to get the property by this function, and set to default value (1843200) if fails. If remove the condition, how to set the default? Thanks.
>
> As I explained above.
>
> x = $default_value;
> device_property_read_u32(..., &x);
I know, thanks.

Huacai
>
> --
> With Best Regards,
> Andy Shevchenko