[PATCH v3 0/3] serial: Support a disabled serial port

[Caleb Connolly]

On 20/11/2024 17:03, Simon Glass wrote:
> Hi Caleb,
> 
> On Wed, 20 Nov 2024 at 08:56, Caleb Connolly <caleb.connolly at linaro.org> wrote:
>>
>> Hi Simon,
>>
>> On 20/11/2024 16:35, Simon Glass wrote:
>>> This series provides a way to tell a serial UART that it can't actually
>>> work, at runtime. The main motivation is to deal with a coreboot feature
>>> where it does not provide UART details in the sysinfo structure unless
>>> the UART is also enabled in coreboot.
>>
>> Why is the UART driver probed if coreboot doesn't provide the necessary
>> info for it?
> 
> U-Boot doesn't do well without some sort of serial device. That could
> perhaps be improved. But the point here is that we need a single
> U-Boot build which can start from coreboot, regardless of what
> coreboot decides to do.

Right, I'm suggesting that at runtime you notice that coreboot didn't
provide a serial port definition (or gave you a bogus address or
something) and skip probing the serial port in that case.
> 
>>
>> Couldn't you disable CONFIG_REQUIRE_SERIAL_CONSOLE and skip probing it?
> 
> No, because I want it to work if the serial info is available.

This option doesn't disable the serial port, it just makes U-Boot not
panic if it can't find one. For example I enable this when building
U-Boot for the upstream supported Qualcomm phones since many don't
enable the serial port in their DTS.
> 
> [..]
> 
> Regards,
> SImon

-- 
// Caleb (they/them)