Re: [PATCH] mgag200 fix memmapsl configuration in GCTL6 register

From: Jocelyn Falempe <jfalempe@redhat.com>
To: Javier Martinez Canillas <javierm@redhat.com>,
	dri-devel@lists.freedesktop.org
Cc: michel@daenzer.net, tzimmermann@suse.de
Subject: Re: [PATCH] mgag200 fix memmapsl configuration in GCTL6 register
Date: Tue, 18 Jan 2022 18:25:48 +0100	[thread overview]
Message-ID: <dca8b176-cd2b-f27d-bdbf-8fd31b29d7af@redhat.com> (raw)
In-Reply-To: <8a8bbee0-1be8-5daa-fc86-dcaae4b78f8c@redhat.com>

On 18/01/2022 18:17, Javier Martinez Canillas wrote:
> On 1/18/22 17:52, Jocelyn Falempe wrote:
>> On 18/01/2022 17:38, Javier Martinez Canillas wrote:
>>> Hello Jocelyn,
>>>
>>> On 1/14/22 10:47, Jocelyn Falempe wrote:
>>
>>>
>>> My worry is if this could cause other issues so I would only do this change
>>> if (is_kdump_kernel()), to make it as non intrusive as possible. And also
>>> add a verbose comment about why this is needed.
>>
>> This change must be done in the "first" kernel, so that when kdump
>> starts, it doesn't hang the machine by writing to the VGA interface, in
>> the early boot code.
>>
> 
> Ah, got it. The patch then makes sense to me as is in that case.
> 
> My comment about documenting why this is needed still applies though.

Yes, I will fix the commit message, and add a comment in the code.
I didn't know 0xA0000 was the graphic mode, so I though the 
configuration was a mistake.
But it turns out, the current configuration is good, but as the driver 
don't use this address, and kdump fails if this address is not VGA text 
mode on some hardware, it's better to set it to 0xb8000.

> 
> Best regards,

Thanks,