From: Thomas Zimmermann <tzimmermann@suse.de>
To: Javier Martinez Canillas <javierm@redhat.com>,
airlied@linux.ie, daniel@ffwll.ch, deller@gmx.de,
maxime@cerno.tech, sam@ravnborg.org, msuchanek@suse.de,
mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org,
geert@linux-m68k.org, mark.cave-ayland@ilande.co.uk
Cc: linux-fbdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
dri-devel@lists.freedesktop.org
Subject: Re: [PATCH v2 07/10] drm/ofdrm: Add ofdrm for Open Firmware framebuffers
Date: Wed, 21 Sep 2022 13:41:42 +0200 [thread overview]
Message-ID: <7e1a2e1d-4635-cb1f-232e-3101ec7b83dc@suse.de> (raw)
In-Reply-To: <c08842d4-f01e-8d75-2b1d-01cf36b55a10@redhat.com>
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Hi
Am 26.07.22 um 15:17 schrieb Javier Martinez Canillas:
> Hello Thomas,
>
> On 7/20/22 16:27, Thomas Zimmermann wrote:
>> Open Firmware provides basic display output via the 'display' node.
>> DT platform code already provides a device that represents the node's
>> framebuffer. Add a DRM driver for the device. The display mode and
>> color format is pre-initialized by the system's firmware. Runtime
>> modesetting via DRM is not possible. The display is useful during
>> early boot stages or as error fallback.
>>
>
> I'm not familiar with OF display but the driver looks good to me.
>
> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
>
> I just have a few questions below.
>
> [...]
>
>> +static int ofdrm_primary_plane_helper_atomic_check(struct drm_plane *plane,
>> + struct drm_atomic_state *new_state)
>> +{
>> + struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(new_state, plane);
>> + struct drm_crtc_state *new_crtc_state;
>> + int ret;
>> +
>> + if (!new_plane_state->fb)
>> + return 0;
>> +
>> + new_crtc_state = drm_atomic_get_new_crtc_state(new_state, new_plane_state->crtc);
>> +
>> + ret = drm_atomic_helper_check_plane_state(new_plane_state, new_crtc_state,
>> + DRM_PLANE_HELPER_NO_SCALING,
>> + DRM_PLANE_HELPER_NO_SCALING,
>> + false, false);
>> + if (ret)
>> + return ret;
>> +
>> + return 0;
>> +}
>
> This seems to be exactly the same check than used in the simpledrm driver.
> Maybe could be moved to the fwfb helper library too ?
I've meanwhile dropped fwfb helpers. Color management requires specific
code here, so there's no much to share anyway.
>
> [...]
>
>> +
>> +static void ofdrm_crtc_helper_atomic_disable(struct drm_crtc *crtc,
>> + struct drm_atomic_state *old_state)
>> +{
>> + /*
>> + * Always enabled; disabling clears the screen in the
>> + * primary plane's atomic_disable function.
>> + */
>> +}
>> +
>
> Same comment than for simpledrm, are these no-op helpers really needed ?
In simpledrm, I've meanwhile removed them. I'll do so here as well.
>
> [...]
>
>> +static const struct of_device_id ofdrm_of_match_display[] = {
>> + { .compatible = "display", },
>> + { },
>> +};
>> +MODULE_DEVICE_TABLE(of, ofdrm_of_match_display);
>> +
>
> I don't see a binding for this in Documentation/devicetree/bindings/display.
> Do we need one or it's that only required for FDT and not Open Firmware DT ?
>
No idea. The device is being created in drivers/of/platform.c. If offb
didn't need these bindings, ofdrm probably won't need them either.
Best regards
Thomas
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev
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next prev parent reply other threads:[~2022-09-21 11:41 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-20 14:27 [PATCH v2 00/10] drm: Add driver for PowerPC OF displays Thomas Zimmermann
2022-07-20 14:27 ` [PATCH v2 01/10] drm/simpledrm: Remove mem field from device structure Thomas Zimmermann
2022-07-25 14:48 ` Javier Martinez Canillas
2022-07-20 14:27 ` [PATCH v2 02/10] drm/simpledrm: Inline device-init helpers Thomas Zimmermann
2022-07-25 15:01 ` Javier Martinez Canillas
2022-07-27 7:50 ` Thomas Zimmermann
2022-07-27 9:30 ` Javier Martinez Canillas
2022-07-20 14:27 ` [PATCH v2 03/10] drm/simpledrm: Remove pdev field from device structure Thomas Zimmermann
2022-07-25 15:02 ` Javier Martinez Canillas
2022-07-20 14:27 ` [PATCH v2 04/10] drm/simpledrm: Compute framebuffer stride if not set Thomas Zimmermann
2022-07-21 14:46 ` Geert Uytterhoeven
2022-07-25 15:13 ` Javier Martinez Canillas
2022-07-27 7:53 ` Thomas Zimmermann
2022-08-11 17:23 ` Daniel Vetter
2022-08-11 18:26 ` Thomas Zimmermann
2022-08-11 18:27 ` Thomas Zimmermann
2022-09-06 19:16 ` Daniel Vetter
2022-07-20 14:27 ` [PATCH v2 05/10] drm/simpledrm: Convert to atomic helpers Thomas Zimmermann
2022-07-25 15:46 ` Javier Martinez Canillas
2022-07-27 7:58 ` Thomas Zimmermann
2022-07-20 14:27 ` [PATCH v2 06/10] drm/simpledrm: Move some functionality into fwfb helper library Thomas Zimmermann
2022-07-25 16:23 ` Javier Martinez Canillas
2022-07-27 8:24 ` Thomas Zimmermann
2022-07-27 9:39 ` Javier Martinez Canillas
2022-07-20 14:27 ` [PATCH v2 07/10] drm/ofdrm: Add ofdrm for Open Firmware framebuffers Thomas Zimmermann
2022-07-26 13:17 ` Javier Martinez Canillas
2022-09-21 11:41 ` Thomas Zimmermann [this message]
2022-07-20 14:27 ` [PATCH v2 08/10] drm/ofdrm: Add CRTC state Thomas Zimmermann
2022-07-26 13:36 ` Javier Martinez Canillas
2022-09-21 11:45 ` Thomas Zimmermann
2022-07-20 14:27 ` [PATCH v2 09/10] drm/ofdrm: Add per-model device function Thomas Zimmermann
2022-07-26 13:38 ` Javier Martinez Canillas
2022-07-26 14:40 ` Michal Suchánek
2022-07-26 19:22 ` Javier Martinez Canillas
2022-07-27 8:33 ` Thomas Zimmermann
2022-08-05 0:22 ` Benjamin Herrenschmidt
2022-09-21 12:37 ` Thomas Zimmermann
2022-07-20 14:27 ` [PATCH v2 10/10] drm/ofdrm: Support color management Thomas Zimmermann
2022-07-26 13:49 ` Javier Martinez Canillas
2022-07-27 8:41 ` Thomas Zimmermann
2022-07-27 9:45 ` Javier Martinez Canillas
2022-08-05 0:29 ` Benjamin Herrenschmidt
2022-08-05 0:19 ` Benjamin Herrenschmidt
2022-09-21 12:55 ` Thomas Zimmermann
2022-09-21 16:48 ` Geert Uytterhoeven
2022-09-22 6:42 ` Thomas Zimmermann
2022-09-22 7:28 ` Maxime Ripard
2022-09-22 8:06 ` Thomas Zimmermann
2022-07-28 11:13 ` [PATCH v2 00/10] drm: Add driver for PowerPC OF displays Michael Ellerman
2022-07-28 11:31 ` Michal Suchánek
2022-07-28 11:42 ` Thomas Zimmermann
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