From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pz2-f41.google.com (mail-pz2-f41.google.com [74.125.228.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 29EB8494831 for ; Wed, 16 Sep 2026 09:45:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.228.41 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789551915; cv=none; b=D9ZoNlDgmTR7AVgnIKvEpjteTpv+T0r798PQRSjIaNrOmf4tsomDu0dW21H33bRcJkvy9XNttPvjT31nvyCm2VZtUV3J8zFQxqgGRmeB81Qthv6wgjgk0nU77Fhp6hH/HStnnKMu9BsyKfDWj+nzfVlUhkWUBlYdw2DFie7647o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789551915; c=relaxed/simple; bh=CqWKEiOFSeRZMC+xXyG4UP7EGxGz2ADL49iwMl9/wWA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=apFxCKW4oSdJ68Vum66JsTXP2CytY0Kgwss7uXnk2O8GbSanjCS/mmwbgVMRLvEehIuvDeohBXpCECvTLxwMSD+cDLsmIMDQhyo/8GWhDitDsjyfZQ+ejhcRBqnvfm4ME4fxdk4m1Y9n+4MbV41KNxzXe9tAEuxiI+XoaHrKRq4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=mhd59BSm; arc=none smtp.client-ip=74.125.228.41 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="mhd59BSm" Received: by mail-pz2-f41.google.com with SMTP id d2e1a72fcca58-85469a3490bso686832b3a.3 for ; Wed, 16 Sep 2026 02:45:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1789551899; x=1790156699; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=SmkBm0qbxpkVGajcugUF9Qtq+Mt2sXz79zpfIKtN2Ss=; b=mhd59BSmeja5+PA+wRTAKTTXhb2o438KlZIMBiqufxQP6K0Cst41jzvKF6sFEvkojm F+xs0pQICUx+kRzIltbzAyqDG+dTpMn094aNswawUkbc4z0nH/FLxJfBjaTtus9MhTzZ rr59YNVEhaMF/4rDvxWb/sHJIRaM8dXztuaw+E/4gPGuzFVFulZHadtOWYGr1Fg/oE3Q K4YKKuq7+ZNIAA7Q1kQAMcas39oi9ydClkkmrShDSD6afPjuEcZ5pBlgsXr3u3/48byJ nZlFOfKofo8xZ2xPDunsPrhECWBhD+schVdHeJWRLkUedNnRJadF4oI2jZ3dWnhq2cf+ urQQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789551899; x=1790156699; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=SmkBm0qbxpkVGajcugUF9Qtq+Mt2sXz79zpfIKtN2Ss=; b=tACJvM1OLzER73/BXg3ottJuBHOmmwsAl7MNh5NGuinH8oE4SXuJqv4qkQWQUIkJp7 kGkX4z+d8pqAlsYzuNBXylAhmGDT6eB/7n2dnwf2YsZmKH6ijUkYuwB4S4mdCImL/ePX jS9bM+RoCUid+Xlj20QoCOrzEW+hdLuHEGRsV1Grec/dMZCJGDGicmOeKNDublG/zeEG +BNiPCVrv60eVYQHPv2B/LaQHgrBObA8vdb8vmudxJln/+X15HbZ8TlseUQuC6v1nB6u V7MoHP2AnfAyAJcP1jHH5WPyugKnfowKxMGqdUzzOU431OHiJVtWsukFFYw1F4g48kQu tv7A== X-Forwarded-Encrypted: i=1; AKwUvByRZL5/aZ12DvhAMN+Ef5l8fMxkRlijcMrL6Ik+iJCaIviwPwSphsAZIva2i0Y+ghy8FaBEt+E7FGzb@vger.kernel.org X-Gm-Message-State: AFuF++me/CWaVRRQOtthCnn1VwyuLKaqSAskF6cLmbayw+mzgGQRael8 9ViahM5+RSvGuKuCwk75lsYv1+16Maa0RnBCdIpi+Y1nm2rDlkpsTrtn X-Gm-Gg: AYBFou3ZaZNIit3a8ffAiCqfz1DDhl+e02TFRwnQCEwmYlzjbOqYNgPKJyy2/gEs7NG yaH2m29Frb5F2x+hzIwwDrzpLsmGySM6HLtV9iExnJf6lz7kTSEvGUu6MiK4oNdWMCRt9+b2DVS fmsOqzRxQNlXgBBdN4V/Hfs1RIk75kK0knucqB0aH7E5PHHSEbtpE3ekeEFq9cRqLzOz7eeCVca opRptGKUijfi/zKBTqsQ5iZmQW3DFknAyiD8Ln9O/ZLah/syNwD2DM8h6fwzLvohohLOf5kcpH6 HcHjKJoNVq+ew3lwLAMVLWQuJ7Apf+VG+h49dk6Lsb7kzJowfo/nW6pd5ub7H4mCa/Hoc/atnkn gWxMH+89whx020SmgklpATKDe/knGG1p8T0rZSTZwvk/8zMzA8MVMFYBt/1JRjICL1cmh6qzFpl tIjug5KjHez/QwiJTDvgeESy/1RCm98q4ihkftUuFEgZ40JhvRBVCioMy7OLELfeuuIXKavQJnn HEnr6r1PUFspu+8UyxBbIDeShSui86pzSJAUh2Nb4l2xvttOwIrGzWYiUmvT1APYxJ4PK+7mZE9 PJMBFORqD9s= X-Received: by 2002:a05:6a00:f04:b0:84f:3f5e:f072 with SMTP id d2e1a72fcca58-8723b391635mr4037389b3a.10.1789551898837; Wed, 16 Sep 2026 02:44:58 -0700 (PDT) Received: from lcwang-Precision-3630-Tower.. (125-227-154-99.hinet-ip.hinet.net. [125.227.154.99]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-87201735415sm942890b3a.42.2026.09.16.02.44.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Sep 2026 02:44:58 -0700 (PDT) From: LiangCheng Wang To: Thomas Zimmermann , Devarsh Thakkar , Maarten Lankhorst , Maxime Ripard , David Airlie , Simona Vetter , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Wig Cheng , Neil Armstrong , Sam Ravnborg Cc: LiangCheng Wang , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Tomi Valkeinen Subject: Re: [PATCH v3 2/2] drm/tiny: add support for PIXPAPER 4.26 monochrome e-ink panel Date: Wed, 16 Sep 2026 17:44:52 +0800 Message-Id: <20260916094453.1062125-1-zaq14760@gmail.com> In-Reply-To: <0a13ccb8-8817-4223-a4a2-0de594ac8c71@suse.de> References: <20260529-bar-v3-0-5c2ac1c751ee@gmail.com> <20260529-bar-v3-2-5c2ac1c751ee@gmail.com> <2bfb73e6-dca3-4d93-af04-3c644929dd19@ti.com> <20260616083921.4066690-1-zaq14760@gmail.com> <423c3dca-9589-488d-8462-c3d51f05ee4a@ti.com> <20260617020926.114947-1-zaq14760@gmail.com> <8fcfab0f-6b98-478b-be4a-c5b810fb3524@ti.com> <20260731035705.3198816-1-zaq14760@gmail.com> <20260916082924.956116-1-zaq14760@gmail.com> <0a13ccb8-8817-4223-a4a2-0de594ac8c71@suse.de> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hi Thomas, Thank you for the quick reply. > Where exactly are these ssd16xx patches. I cannot find them in the DRM > trees. I presume they are not upstream yet? That is right, they are not upstream. Devarsh posted them on 1 May and the series is still at v1 on the list: [PATCH 0/6] Add DRM driver for Solomon SSD16xx e-paper display controllers https://lore.kernel.org/all/20260430183311.2978142-1-devarsht@ti.com/ One thing that is easy to miss, and that I should have made clearer in my last mail: that v1 series covers the SSD1683 only. The SSD1677, which is the controller on the PIXPAPER 4.26m, is not part of it. Devarsh has SSD1677 support in a staged branch that he kindly shared with me in July, and that is what I tested on the panel: https://github.com/devarsht/linux-next/commits/ssd16xx_7_2/ Those SSD1677 patches have not been posted to the list yet, which is why the panel support has not had anything to build on so far. > If there's support for similar ICs, I'd strongly prefer to have the > ssd1677 be part of that instead of a stand-alone driver. > > Once the stand-alone driver is in place, users will rely on it. Then it > becomes hard to replace. We had (have?) cases where there are several > drivers for the same hardware. Understood, and thank you for explaining the reasoning - the point about users coming to depend on a driver that is then hard to replace makes sense, and I would rather not create that problem. I will drop the standalone driver and add the PIXPAPER 4.26m to ssd16xx instead, once the shared driver is in. Devarsh, thank you again for sharing the branch, and for making room for the panel in your work in the first place. I am glad to keep testing SSD1677 on real hardware whenever that is useful to you. Regards, LiangCheng