On Tue, Oct 20, 2020 at 07:08:47AM +0200, Ahmad Fatoum wrote:
> Hello Uwe,
> 
> On 9/18/20 1:04 PM, Uwe Kleine-König wrote:
> > For most machines having DRIVER_SERIAL_NS16550 and DRIVER_SERIAL_EFI_STDIO
> > both enabled results in the output appearing twice on the serial output.
> > So remove disable the lowlevel driver and rely on the EFI bios for serial.

How embarrassing, s/remove //.

> On the flip-side, some systems now won't output anything over serial with
> the defconfig, like the one I just ran into. Maybe we should keep both
> enabled, but have a quirk table, which boards to disable the 16550 for?

Expecting that most systems are happy with EFI_STDIO I would suggest a
quirk table for those systems which are not?!

> My board is
>   EFI v2.40 by American Megatrends v327691". What's yours?
>   barebox@barebox EFI payload:/ devinfo acpi-FACP0
>   [...]
>   Revision: 5
>   OemId: ALASKA
>   OemTableId: A M I
>   OemRevision: 17244169
>   CreatorId: 0x20494d41
>   CreatorRevision: 65555
> 
> What's yours?

I saw the doubled output on my Laptop (Lenovo T460p).

dmidecode has:

	BIOS Information
		Vendor: LENOVO
		Version: R07ET81W (2.21 )
		Release Date: 12/18/2017
		Address: 0xE0000
		Runtime Size: 128 kB
		ROM Size: 16 MB
		Characteristics:
			PCI is supported
			PNP is supported
			BIOS is upgradeable
			BIOS shadowing is allowed
			Boot from CD is supported
			Selectable boot is supported
			EDD is supported
			3.5"/720 kB floppy services are supported (int 13h)
			Print screen service is supported (int 5h)
			8042 keyboard services are supported (int 9h)
			Serial services are supported (int 14h)
			Printer services are supported (int 17h)
			CGA/mono video services are supported (int 10h)
			ACPI is supported
			USB legacy is supported
			BIOS boot specification is supported
			Targeted content distribution is supported
			UEFI is supported
		BIOS Revision: 2.21
		Firmware Revision: 1.4

(This is the system I write this mail on, I don't feel like rebooting to check
devinfo in barebox, take a picture and then type the stuff into a mail
by hand.)

Best regards
Uwe


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Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |