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From:   Vitaly Kuznetsov <vkuznets@redhat.com>
To:     Matthew Wilcox (Oracle) <willy@infradead.org>,
        dri-devel@lists.freedesktop.org, linux-hyperv@vger.kernel.org,
        linux-fbdev@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org,
        Michael Kelley <mikelley@microsoft.com>, wei.liu@kernel.org,
        Dexuan Cui <decui@microsoft.com>
Subject: [bug report] Commit ccf953d8f3d6 ("fb_defio: Remove custom
 address_space_operations") breaks Hyper-V FB driver
Date:   Fri, 04 Jun 2021 14:25:01 +0200
Message-ID: <87v96tzujm.fsf@vitty.brq.redhat.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

Hi,

Commit ccf953d8f3d6 ("fb_defio: Remove custom address_space_operations")
seems to be breaking Hyper-V framebuffer
(drivers/video/fbdev/hyperv_fb.c) driver for me: Hyper-V guest boots
well and plymouth even works but when I try starting Gnome, virtual
screen just goes black. Reverting the above mentioned commit on top of
5.13-rc4 saves the day. The behavior is 100% reproducible. I'm using
Gen2 guest runing on Hyper-V 2019. It was also reported that Gen1 guests
are equally broken.

Is this something known?

-- 
Vitaly