From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f53.google.com (mail-wr1-f53.google.com [209.85.221.53]) (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 1D0AF20967F for ; Mon, 7 Apr 2025 16:27:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744043271; cv=none; b=iksNlVeqQ456jFqYst5ZmYv5XTR/M2/ZH0hnKelpx6RgeX/IztITgyq0t1i2M0M6Y2x/vysH7RqxCNQNtNpoo/QhrO07kpm/nGH5fmWPCdAZUHZg9vVONn4qKhZDGxrkG74m92uHp33uznC4D2nKF/iMeoVtalG//rrawLryEhk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744043271; c=relaxed/simple; bh=ixu4OFoJwzg1v+1wl51xk03lO5q8ieoco/QoCpn/be4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cIQ0DvNnYYEKEcmn95ms8ist/F/xB3cK4lbHw9Ej3HTioSqXFUIXuvQ7QpUQsejPvtX8KOIjh6QL5D+csMn6x5wohH9qwdYYXfLGx8w//4INp649xeuH/0w6W/NNQvS01qfzFPyoUinN7keBHSusFUwfnBcMUORDXLEpBY6Hh1Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=riscstar.com; spf=pass smtp.mailfrom=riscstar.com; dkim=pass (2048-bit key) header.d=riscstar-com.20230601.gappssmtp.com header.i=@riscstar-com.20230601.gappssmtp.com header.b=CJjPujMh; arc=none smtp.client-ip=209.85.221.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=riscstar.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=riscstar.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=riscstar-com.20230601.gappssmtp.com header.i=@riscstar-com.20230601.gappssmtp.com header.b="CJjPujMh" Received: by mail-wr1-f53.google.com with SMTP id ffacd0b85a97d-39bf44be22fso3102000f8f.0 for ; Mon, 07 Apr 2025 09:27:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=riscstar-com.20230601.gappssmtp.com; s=20230601; t=1744043267; x=1744648067; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=Gmt4HX/iSNiSTqkD3t3ALwtpmvWnuIuBQoVi+iO2Lmc=; b=CJjPujMhKpR8Ka2qInFujzInJVSRNAgpGLfDvBTxTRZtTXaVur3Y4xK68UyceaFHh7 7pPcqYdXqsa3XhfsWV0/OCq8L0m2LkA13N9k2HWQ9jFAGeXSB3ShLkhRFB6HOSZxDa1N N3vu0K0ProzdEcBTfluMRCpfE2vYHJqpcrTdHD+QqbFa/H9bVk3kuPHNgRg7wysgFu/4 y6vYEbehUyBMWDRBATOJszi25NbagcmcvmZvcbey2LB0VhWms1V8dCnMC8FWLkLR3ngM 5UoAxTaM4V7MkSez7t41faMXV+SGO2jr+azrbjVPwet8CIgtQIsDNWfklXQ3PNVnnltN aSkw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1744043267; x=1744648067; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Gmt4HX/iSNiSTqkD3t3ALwtpmvWnuIuBQoVi+iO2Lmc=; b=ggQSelOWMW2Pen0dlqKZSM7RHOoWxv1f6Jf7AYvT7aMh4Yy2ZsYh42T8lLCIqyFJJZ wb+0SoMRv/4cESH37P5iRRQ59zLnQvMa2l0kjrapE5CnIQ6d6kbWfr08LVq4Sbd3xVXl bco0tD3yIjDKp+4vg08jCrv13xU8EhlrR+TFXgV0RsJ+FZolWNR2n3FqQAon8Fzvi7gC +yS8erJS1rZc+fmq1kmvaBIhbpmihNNuz0cyUlkTRC2Bfvdj6GUQIUKByR0Y2ip7sjo2 7NMwmheVrlGvHLtNrpl8kqROVCzftL5LhBdUhT14DwSUXr3zK5YnPR32XoUFjjEDyL8/ XugA== X-Forwarded-Encrypted: i=1; AJvYcCVL35i+Djc+RStT0nmQIBqv1MTdHzgScN4QuUo5WCpK7asoBtRWJy9zWh3MIfqJPlxhjz8Al3Hf7Hpq1A==@vger.kernel.org X-Gm-Message-State: AOJu0Ywpykq/avl+42MQMNhEMEl0uf7bg2KSgCVmCAWGUu3gLxia9V+L SWxhcCYG+hxKcMIRZRbqlYeBAqmY/yj/HfNgc4LTREc08+vG93H0YRCCsXBrfmA= X-Gm-Gg: ASbGncukLp+9S/0gNpCRWgVMJ4t6pw6WOqXQPEzbrsvNTMMvzS5QzTxiao8kelq13Ti ugdiBeDF+dXzD3zCT5vqE1i8mIvAuP6rPWPyfiyM8dehtMRD7f0+ylelsONcDZYtF4O7XjTJFkD bWTBcnpv2684cndi4QkyB7XBUkUFOWLT8JzXZivIXQULj7MO5IOa5G0Ej2vmOeUttteV7ntGEwE Xzu9J96kik4s4KDJVrvd1OPUuQwpbFZR9BTOYkt5Ym6nTk2ZAYXCRRxqO3TrcEO1Y3HDjnrQtyt eldO01Xlqm/ti2TnXecaHG93NzeDDPzq0qviVHeUH7LnAoj1yomn97XqXCFrmZQv2qxqcyxuamS hFrAlMx/w0H+9FPXR1WccarPoKDU= X-Google-Smtp-Source: AGHT+IG8J3er1iyXQBPMxITzMvfz9EFr3jDi7ygtRVXk9vTgIkpVU04qGBBpxMY6//a+NXkI/WoaMA== X-Received: by 2002:a05:6000:1786:b0:39c:1f02:449f with SMTP id ffacd0b85a97d-39d6fc00d2dmr6036975f8f.2.1744043267049; Mon, 07 Apr 2025 09:27:47 -0700 (PDT) Received: from aspen.lan (aztw-34-b2-v4wan-166919-cust780.vm26.cable.virginm.net. [82.37.195.13]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-43ec34a92desm134263455e9.14.2025.04.07.09.27.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Apr 2025 09:27:46 -0700 (PDT) Date: Mon, 7 Apr 2025 17:27:44 +0100 From: Daniel Thompson To: Pengyu Luo Cc: Jianhua Lu , Lee Jones , Daniel Thompson , Jingoo Han , Pavel Machek , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Helge Deller , dri-devel@lists.freedesktop.org, linux-leds@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org Subject: Re: [PATCH 2/4] backlight: ktz8866: add slave handler Message-ID: References: <20250407095119.588920-1-mitltlatltl@gmail.com> <20250407095119.588920-3-mitltlatltl@gmail.com> Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250407095119.588920-3-mitltlatltl@gmail.com> On Mon, Apr 07, 2025 at 05:51:17PM +0800, Pengyu Luo wrote: > Kinetic ktz8866, found in many android devices, nowadays, some oem use > dual ktz8866 to support a larger panel and higher brightness, original > driver would only handle half backlight region on these devices, > registering it twice is unreasonable, so adding the slave handler to > support it. Is there anything unique about KTZ8866 that allows it to be used like this? I think it would be better to add support for secondary backlight controllers into the backlight framework, rather than having to implement driver specific hacks for every backlight controller that appears in a primary/secondary configuration. Also, the kernel seeks to avoid adding new instances of master/slave terminology. See the coding style doc for suggested alternatives: https://www.kernel.org/doc/html/latest/process/coding-style.html#naming Daniel.