mail archive of the barebox mailing list
 help / color / mirror / Atom feed
From: Ahmad Fatoum <a.fatoum@pengutronix.de>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	barebox@lists.infradead.org
Subject: Re: [PATCH 2/2] x86/config/efi: drop DRIVER_SERIAL_NS16550
Date: Mon, 26 Oct 2020 22:07:19 +0100	[thread overview]
Message-ID: <bea5dc47-adc4-4096-9617-7d99e48e599e@pengutronix.de> (raw)
In-Reply-To: <20201026180649.GQ30556@pengutronix.de>



On 10/26/20 7:06 PM, Michael Olbrich wrote:
> On Tue, Oct 20, 2020 at 09:35:30AM +0200, Ahmad Fatoum wrote:
>> On 10/20/20 9:26 AM, Uwe Kleine-König wrote:
>>> 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?!
>>
>> Doubled output is better than no output, so a defconfig that
>> by default displays anything if the BIOS is not in the quirk
>> table sounds like it's the better choice?
> 
> Maybe disable CONSOLE_ACTIVATE_ALL instead? Then you should only get the
> output from one driver.

And which one should be default? You'll get more compile time coverage
with the defconfig but the user experience problem of having a defconfig
that does print nothing at all on some devices is still there.

> 
> Michael
> 
>>>
>>>> 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).
>>
>> You have serial output on your laptop?
>>
>>>
>>> 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
>>>
>>>
>>
>> -- 
>> Pengutronix e.K.                           |                             |
>> Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>> 31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
>>
>> _______________________________________________
>> barebox mailing list
>> barebox@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/barebox
>>
> 

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

  reply	other threads:[~2020-10-26 21:07 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-18 11:04 [PATCH 1/2] Regenerate defconfig files Uwe Kleine-König
2020-09-18 11:04 ` [PATCH 2/2] x86/config/efi: drop DRIVER_SERIAL_NS16550 Uwe Kleine-König
2020-10-20  5:08   ` Ahmad Fatoum
2020-10-20  7:26     ` Uwe Kleine-König
2020-10-20  7:35       ` Ahmad Fatoum
2020-10-26 18:06         ` Michael Olbrich
2020-10-26 21:07           ` Ahmad Fatoum [this message]
2020-10-28  8:38             ` Sascha Hauer
2020-09-23  8:47 ` [PATCH 1/2] Regenerate defconfig files Sascha Hauer

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=bea5dc47-adc4-4096-9617-7d99e48e599e@pengutronix.de \
    --to=a.fatoum@pengutronix.de \
    --cc=barebox@lists.infradead.org \
    --cc=u.kleine-koenig@pengutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox