From: Christian Zigotzky <chzigotzky@xenosoft.de>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "Darren Stevens" <darren@stevens-zone.net>,
"R.T.Dickinson" <rtd2@xtra.co.nz>,
"Thomas Zimmermann" <tzimmermann@suse.de>,
kraxel@cs.tu-berlin.de,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
"Michel Dänzer" <michel@daenzer.net>,
"Maling list - DRI developers" <dri-devel@lists.freedesktop.org>,
"mad skateman" <madskateman@gmail.com>,
deller@gmx.de
Subject: Re: Fbdev issue after the drm updates 'drm-next-2023-10-31-1'
Date: Mon, 13 Nov 2023 14:12:03 +0100 [thread overview]
Message-ID: <c13fcf82-3bf0-447e-9ac5-b33db0e38f07@xenosoft.de> (raw)
In-Reply-To: <CAMuHMdU-8Fu55C2zu_XxmG8n5paOQYfqNA84JNvXo4c87D-kFw@mail.gmail.com>
On 13 November 2023 at 01:48 pm, Geert Uytterhoeven wrote:
> Hi Christian,
>
> On Sun, Nov 12, 2023 at 3:23 PM Christian Zigotzky
> <chzigotzky@xenosoft.de> wrote:
>> On 07 November 2023 at 09:36 am, Christian Zigotzky wrote:
>>> I have found out that fbdev no longer works with virtio-gpu-pci and
>>> virtio-vga. It is not a problem with the penguin logos.
>>>
>>> Could you please check fbdev in QEMU virtual machines with
>>> virtio-gpu-pci and virtio-vga graphics?
>>> On 02 November 2023 at 03:45 pm, Christian Zigotzky wrote:
>>>> There is a fbdev issue with the virtio-gpu-pci and virtio-vga. (The
>>>> penguins are not displayed at boot time)
>>>>
>>>> Error message: [ 0.889302] virtio-pci 0000:00:02.0: [drm] *ERROR*
>>>> fbdev: Failed to setup generic emulation (ret=-2)
>>>>
>>>> The kernel 6.6 final doesn't have this issue.
>>>>
>>>> Please check the fbdev changes in the drm updates
>>>> 'drm-next-2023-10-31-1'.
> Thanks for your report!
>
> I can confirm there is no graphics output with m68k/virt, and
> bisected this to my own commit 6ae2ff23aa43a0c4 ("drm/client: Convert
> drm_client_buffer_addfb() to drm_mode_addfb2()"), ouch...
>
> It turns out the old call to drm_mode_addfb() caused a translation
> from a fourcc to a bpp/depth pair to a _different_ fourcc, due to the
> quirk processing in drm_driver_legacy_fb_format().
> I.e. on m68k/virt, the original requested format was XR24, which was
> translated to BX24. The former doesn't work, the latter works.
>
> The following (gmail-whitespace-damaged) patch fixed the issue for me:
>
> --- a/drivers/gpu/drm/drm_client.c
> +++ b/drivers/gpu/drm/drm_client.c
> @@ -400,6 +400,16 @@ static int drm_client_buffer_addfb(struct
> drm_client_buffer *buffer,
>
> fb_req.width = width;
> fb_req.height = height;
> + if (client->dev->mode_config.quirk_addfb_prefer_host_byte_order) {
> + if (format == DRM_FORMAT_XRGB8888)
> + format = DRM_FORMAT_HOST_XRGB8888;
> + if (format == DRM_FORMAT_ARGB8888)
> + format = DRM_FORMAT_HOST_ARGB8888;
> + if (format == DRM_FORMAT_RGB565)
> + format = DRM_FORMAT_HOST_RGB565;
> + if (format == DRM_FORMAT_XRGB1555)
> + format = DRM_FORMAT_HOST_XRGB1555;
> + }
> fb_req.pixel_format = format;
> fb_req.handles[0] = handle;
> fb_req.pitches[0] = buffer->pitch;
>
> However, I don't think we want to sprinkle more of these
> translations around... So perhaps we should (re)add a call to
> drm_driver_legacy_fb_format() to drm_client_buffer_addfb()?
>
> Second, as I doubt you are using a big-endian system, you are probably
> running into a slightly different issue.
>
> Oh wait, you did CC linuxppc-dev, so perhaps you are running on a
> big-endian machine?
>
> If not, please add
>
> pr_info("%s: format = %p4cc\n", __func__, &format);
>
> to drivers/gpu/drm/drm_client.c:drm_client_buffer_addfb(), and,
> after reverting commit 6ae2ff23aa43a0c4, add
>
> pr_info("%s: bpp %u/depth %u => r.pixel_format = %p4cc\n",
> __func__, or->bpp, or->depth, &r.pixel_format);
>
> to drivers/gpu/drm/drm_framebuffer.c:drm_mode_addfb(), so we know the
> translation in your case?
>
> Thanks!
>
> Gr{oetje,eeting}s,
>
> Geert
>
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
Hi Geert,
Thanks for your answer! I use a big-endian system.
Cheers,
Christian
next prev parent reply other threads:[~2023-11-13 13:12 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-30 11:59 Radeon NI: GIT kernel with the nislands_smc commit doesn't boot on a Freescale P5040 board and P.A.Semi Nemo board Christian Zigotzky
2021-04-30 15:26 ` Deucher, Alexander
2021-04-30 15:56 ` Gustavo A. R. Silva
2021-05-06 23:55 ` Gustavo A. R. Silva
2021-05-07 6:43 ` Christian Zigotzky
2021-05-08 11:33 ` Christian Zigotzky
2021-05-09 23:04 ` Gustavo A. R. Silva
2023-11-02 14:45 ` Fbdev issue after the drm updates 'drm-next-2023-10-31-1' Christian Zigotzky
2023-11-07 8:36 ` Christian Zigotzky
2023-11-12 14:23 ` Christian Zigotzky
2023-11-13 12:48 ` Geert Uytterhoeven
2023-11-13 13:12 ` Christian Zigotzky [this message]
2023-11-14 9:45 ` Christian Zigotzky
2023-11-15 8:33 ` Geert Uytterhoeven
2023-11-15 9:22 ` Gerd Hoffmann
2023-11-16 13:13 ` Geert Uytterhoeven
2021-11-04 10:45 ` [VirtIO GPU] Xorg doesn't start with the DRM updates 'drm-next-2021-11-03' in a virtual e5500 QEMU KVM-HV machine on a Freescale P5040 board Christian Zigotzky
2021-11-04 21:42 ` [PATCH] drm/virtio: Fix NULL dereference error in virtio_gpu_poll Vivek Kasireddy
2021-11-05 18:05 ` Christian Zigotzky
2021-11-08 12:56 ` Gerd Hoffmann
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