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Date:   Fri, 17 Jun 2022 08:46:18 +0200
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Subject: Re: [PATCH v6 3/5] fbdev: Disable sysfb device registration when
 removing conflicting FBs
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To:     Zack Rusin <zackr@vmware.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc:     "linux-fbdev@vger.kernel.org" <linux-fbdev@vger.kernel.org>,
        "kraxel@redhat.com" <kraxel@redhat.com>,
        "tzimmermann@suse.de" <tzimmermann@suse.de>,
        "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "alex.williamson@redhat.com" <alex.williamson@redhat.com>,
        "dri-devel@lists.freedesktop.org" <dri-devel@lists.freedesktop.org>,
        "daniel.vetter@ffwll.ch" <daniel.vetter@ffwll.ch>,
        "lersek@redhat.com" <lersek@redhat.com>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "deller@gmx.de" <deller@gmx.de>,
        Linux-graphics-maintainer <Linux-graphics-maintainer@vmware.com>
References: <20220607182338.344270-1-javierm@redhat.com>
 <20220607182338.344270-4-javierm@redhat.com>
 <de83ae8cb6de7ee7c88aa2121513e91bb0a74608.camel@vmware.com>
 <38473dcd-0666-67b9-28bd-afa2d0ce434a@redhat.com>
 <603e3613b9b8ff7815b63f294510d417b5b12937.camel@vmware.com>
 <a633d605-4cb3-2e04-1818-85892cf6f7b0@redhat.com>
 <97565fb5-cf7f-5991-6fb3-db96fe239ee8@redhat.com>
 <711c88299ef41afd8556132b7c1dcb75ee7e6117.camel@vmware.com>
From:   Javier Martinez Canillas <javierm@redhat.com>
In-Reply-To: <711c88299ef41afd8556132b7c1dcb75ee7e6117.camel@vmware.com>
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Hello Zack,

On 6/17/22 03:35, Zack Rusin wrote:
> On Fri, 2022-06-17 at 01:21 +0200, Javier Martinez Canillas wrote:
>> On 6/17/22 00:18, Javier Martinez Canillas wrote:
>>> On 6/16/22 23:03, Zack Rusin wrote:
>>
>> [snip]
>>
>>>
>>> I'll look at this tomorrow but in the meantime, could you please look if the following
>>> commits on top of drm-misc-next help ?
>>>
>>> d258d00fb9c7 fbdev: efifb: Cleanup fb_info in .fb_destroy rather than .remove
>>> 1b5853dfab7f fbdev: efifb: Fix a use-after-free due early fb_info cleanup
>>>
>>
>> Scratch that. I see in your config now that you are not using efifb but instead
>> simpledrm: CONFIG_DRM_SIMPLEDRM=y, CONFIG_SYSFB_SIMPLEFB=y and CONFIG_DRM_VMWGFX.
>>
>> Since you mentioned efifb I misunderstood that you are using it. Anyways, as
>> said I'll investigate this tomorrow.
> 
> Sounds good. Let me know if you'd like me to try it without SIMPLEFB.
>

Yes, please do. Either with CONFIG_SYSFB_SIMPLEFB disabled and CONFIG_FB_EFI
enabled (so that "efi-framebuffer" is registered and efifb probed) or with
CONFIG_SYSFB_SIMPLEFB but CONFIG_FB_SIMPLE enabled (so "simple-framebuffer
is used too but with simplefb instead of simpledrm).
 
I'm not able to reproduce, it would be useful to have another data point.

-- 
Best regards,

Javier Martinez Canillas
Linux Engineering
Red Hat