Message-ID: <064dd2b7-415b-4794-8867-73bdd7ac17df@suse.de>
Date: Wed, 28 Jan 2026 09:54:03 +0100
From: Thomas Zimmermann <tzimmermann@...e.de>
To: Icenowy Zheng <uwu@...nowy.me>, Andrzej Hajda <andrzej.hajda@...el.com>,
 Neil Armstrong <neil.armstrong@...aro.org>, Robert Foss <rfoss@...nel.org>,
 Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
 Jonas Karlman <jonas@...boo.se>, Jernej Skrabec <jernej.skrabec@...il.com>,
 Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
 Maxime Ripard <mripard@...nel.org>, David Airlie <airlied@...il.com>,
 Simona Vetter <simona@...ll.ch>, Rob Herring <robh@...nel.org>,
 Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley
 <conor+dt@...nel.org>, Drew Fustini <fustini@...nel.org>,
 Guo Ren <guoren@...nel.org>, Fu Wei <wefu@...hat.com>
Cc: Philipp Zabel <p.zabel@...gutronix.de>,
 Dmitry Baryshkov <lumag@...nel.org>,
 Michal Wilczynski <m.wilczynski@...sung.com>,
 Luca Ceresoli <luca.ceresoli@...tlin.com>, Han Gao <rabenda.cn@...il.com>,
 Yao Zi <ziyao@...root.org>, linux-kernel@...r.kernel.org,
 dri-devel@...ts.freedesktop.org, devicetree@...r.kernel.org,
 linux-riscv@...ts.infradead.org, Han Gao <gaohan@...as.ac.cn>
Subject: Re: [PATCH v6 3/9] drm: verisilicon: add a driver for Verisilicon
 display controllers

Hi

Am 28.01.26 um 09:39 schrieb Icenowy Zheng:
> 在 2026-01-28星期三的 08:58 +0100，Thomas Zimmermann写道：
>> Hi
>>
>> Am 23.01.26 um 10:28 schrieb Icenowy Zheng:
>>> From: Icenowy Zheng <uwu@...nowy.me>
>>>
>>> This is a from-scratch driver targeting Verisilicon DC-series
>>> display
>>> controllers, which feature self-identification functionality like
>>> their
>>> GC-series GPUs.
>>>
>>> Only DC8200 is being supported now, and only the main framebuffer
>>> is set
>>> up (as the DRM primary plane). Support for more DC models and more
>>> features is my further targets.
>>>
>>> As the display controller is delivered to SoC vendors as a whole
>>> part,
>>> this driver does not use component framework and extra bridges
>>> inside a
>>> SoC is expected to be implemented as dedicated bridges (this driver
>>> properly supports bridge chaining).
>>>
>>> Signed-off-by: Icenowy Zheng <uwu@...nowy.me>
>>> Signed-off-by: Icenowy Zheng <zhengxingda@...as.ac.cn>
>>> Tested-by: Han Gao <gaohan@...as.ac.cn>
>>> Tested-by: Michal Wilczynski <m.wilczynski@...sung.com>
>> Reviewed-by: Thomas Zimmermann <tzimmermann@...e.de>
>>
>> I only briefly looked over this revision, as v5 already seemed quite
>> good. If you want to do a follow-up patch, see my other reply to v5
>> on
>> storing hardware formats in the plane state.
> Well the kernel test robot found a small Kconfig problem in this
> revision -- DRM_DISPLAY_HELPER should be selected.
>
> Maybe I'm going to send a v7 to address this.
>
> Should I also make derived plane state a change in v7, or leave it as a
> follow-up?

That would require another round of review, I guess. Better leave it for 
a separate series.

>
> By the way, I think PATCH 1-5 should go through drm-misc tree, am I
> right? Who's going to pick it if going through drm-misc?

I can do that. In v7, you can merge patch 8 (MAINTAINERS) into patch 3, 
so that it goes in as well.

Patches 6 and 7 are small, so I can also take them into drm-misc if they 
riscv maintainers are OK with that.

Best regards
Thomas

>
>> Best regards
>> Thomas
>>
>>> ---
>>> Changes in v6:
>>> - Sorted Kconfig dependency.
>>> - Get rid of obsolete uppercase DRM_* printk marcos.
>>> - Optimization to printk messages (unknown IRQ message is only
>>> printed
>>>     once, device recognition message has "Found" added, "Skipping
>>> output"
>>>     message priority lowered to debug).
>>> - Splitted most bridge functions for DPI/DP output.
>>> - Get rid of custom CRTC atomic_flush, which doesn't do anything
>>>     device-specific.
>>> - Adapted macro HZ_PER_KHZ and VSDC_DISP_TIMING_VALUE_MAX.
>>> - Switched to use drm_mode_size_dumb() to align dumb buffer pitch.
>>> - Reordered some function calls in vs_drm_initialize() (
>>>     aperture_remove_all_conflicting_devices() is now called earlier
>>> and
>>>     drm_mode_config_reset() is now called later).
>>> - Splitted out vs_fb_get_dma_addr() and switched to use
>>>     drm_format_info_min_pitch() to calculate the src X offset to the
>>>     framebuffer address.
>>> - Splitted out atomic_{en,dis}able for primary plane.
>>> - Removed an unused pm_runtime.h inclusion because the driver now
>>> does
>>>     not do runpm.
>>>
>>> Changes in v5:
>>> - Switching to drm_atomic_get_new_bridge_state, which seems to let
>>> the
>>>     driver get rid of the hack of saving bus format itself.
>>> - Add the internal bridge before attaching it.
>>> - Adapted next_bridge struct field name suggested by Luca Ceresoli.
>>> - Refactored the probe code to not use port count, to allow port@0
>>> being
>>>     missing.
>>>
>>> Changes in v4:
>>> - Switch to drm_* logger when we're handling with struct
>>> drm_device.
>>>
>>> Changes in v3:
>>> - Get rid of drm_atomic_get_existing_crtc_state() which is marked
>>>     deprecated.
>>>
>>> Changes in v2:
>>> - Changed some Control flows according to previous reviews.
>>> - Added missing of_node_put when checking of endpoints for output
>>> type.
>>> - Switched all userspace-visible modeset objects to be managed by
>>> drmm
>>>     instead of devm.
>>> - Utilize devm_drm_bridge_alloc() in internal bridge.
>>> - Prevented the usage of simple encoder helpers by passing a NULL
>>> funcs pointer.
>>> - Let devm enable clocks when getting them.
>>> - Removed explicit `.cache_type = REGCACHE_NONE` in regmap config.
>>> - Fixed a debug print using a variable before initialization.
>>> - Fixed a wrong index when using bulk to handle resets.
>>> - Added missing configuration for DPI format (currently fixed
>>> RGB888).
>>>
>>>    drivers/gpu/drm/Kconfig                       |   2 +
>>>    drivers/gpu/drm/Makefile                      |   1 +
>>>    drivers/gpu/drm/verisilicon/Kconfig           |  15 +
>>>    drivers/gpu/drm/verisilicon/Makefile          |   5 +
>>>    drivers/gpu/drm/verisilicon/vs_bridge.c       | 371
>>> ++++++++++++++++++
>>>    drivers/gpu/drm/verisilicon/vs_bridge.h       |  39 ++
>>>    drivers/gpu/drm/verisilicon/vs_bridge_regs.h  |  54 +++
>>>    drivers/gpu/drm/verisilicon/vs_crtc.c         | 191 +++++++++
>>>    drivers/gpu/drm/verisilicon/vs_crtc.h         |  31 ++
>>>    drivers/gpu/drm/verisilicon/vs_crtc_regs.h    |  60 +++
>>>    drivers/gpu/drm/verisilicon/vs_dc.c           | 207 ++++++++++
>>>    drivers/gpu/drm/verisilicon/vs_dc.h           |  38 ++
>>>    drivers/gpu/drm/verisilicon/vs_dc_top_regs.h  |  27 ++
>>>    drivers/gpu/drm/verisilicon/vs_drm.c          | 182 +++++++++
>>>    drivers/gpu/drm/verisilicon/vs_drm.h          |  28 ++
>>>    drivers/gpu/drm/verisilicon/vs_hwdb.c         | 150 +++++++
>>>    drivers/gpu/drm/verisilicon/vs_hwdb.h         |  29 ++
>>>    drivers/gpu/drm/verisilicon/vs_plane.c        | 124 ++++++
>>>    drivers/gpu/drm/verisilicon/vs_plane.h        |  72 ++++
>>>    .../gpu/drm/verisilicon/vs_primary_plane.c    | 173 ++++++++
>>>    .../drm/verisilicon/vs_primary_plane_regs.h   |  53 +++
>>>    21 files changed, 1852 insertions(+)
>>>    create mode 100644 drivers/gpu/drm/verisilicon/Kconfig
>>>    create mode 100644 drivers/gpu/drm/verisilicon/Makefile
>>>    create mode 100644 drivers/gpu/drm/verisilicon/vs_bridge.c
>>>    create mode 100644 drivers/gpu/drm/verisilicon/vs_bridge.h
>>>    create mode 100644 drivers/gpu/drm/verisilicon/vs_bridge_regs.h
>>>    create mode 100644 drivers/gpu/drm/verisilicon/vs_crtc.c
>>>    create mode 100644 drivers/gpu/drm/verisilicon/vs_crtc.h
>>>    create mode 100644 drivers/gpu/drm/verisilicon/vs_crtc_regs.h
>>>    create mode 100644 drivers/gpu/drm/verisilicon/vs_dc.c
>>>    create mode 100644 drivers/gpu/drm/verisilicon/vs_dc.h
>>>    create mode 100644 drivers/gpu/drm/verisilicon/vs_dc_top_regs.h
>>>    create mode 100644 drivers/gpu/drm/verisilicon/vs_drm.c
>>>    create mode 100644 drivers/gpu/drm/verisilicon/vs_drm.h
>>>    create mode 100644 drivers/gpu/drm/verisilicon/vs_hwdb.c
>>>    create mode 100644 drivers/gpu/drm/verisilicon/vs_hwdb.h
>>>    create mode 100644 drivers/gpu/drm/verisilicon/vs_plane.c
>>>    create mode 100644 drivers/gpu/drm/verisilicon/vs_plane.h
>>>    create mode 100644 drivers/gpu/drm/verisilicon/vs_primary_plane.c
>>>    create mode 100644
>>> drivers/gpu/drm/verisilicon/vs_primary_plane_regs.h

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)

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