From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.8]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 708C0158A04; Wed, 28 Aug 2024 07:51:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.8 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724831484; cv=none; b=WUQ4JXYu4CAoA21kDPfkOrZbK0axtiNAlMRsri2/bjC1FS7BcH6GL6kT/7Da/KDML+WUDmB1LZsZAKlBZIio0EQYGApsH+qM3OhlM2yME1/AtmsNWBRRkF/2/4kbTnXP2l23b1/KDSw0jEZ6JRrD4W839ERzK/yN1uPAnL9jNUA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724831484; c=relaxed/simple; bh=g6S7cgkwyHTYMqfsr52CVhpQrrl8Vy5/S/YFliyHNKE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qaXKnLJjuH5HzYm+U4Fs63anXSdT9aDyrf5i56xl95lKxOw4whp0lowK8HNAMYun2KiDBTNkItZEbtiji6aRAhMHaxXnEjJ0Oe/WmZc94rrdjMjU1z9Qo/hNmQ/MRmQX+ehX1p+WhxSUXLRCNVQANjFnQ3iTZpRI3WoHmxDAchg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=TEGld0Zr; arc=none smtp.client-ip=192.198.163.8 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="TEGld0Zr" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1724831482; x=1756367482; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=g6S7cgkwyHTYMqfsr52CVhpQrrl8Vy5/S/YFliyHNKE=; b=TEGld0ZrtBHs4WRW0gJqK+MgU3l59FRUQ9xQUl9JuNkUeQr3k1wqEeiC sCo4VcFAPC2ijqsqnaq1zMEQ2xwYExwvctYpgEYExcQ1ZHrFGeOgMFNi8 NAWhEcmQzTLhtRMqeDoKOGjQHpokRWpXYUrb43hNWLeqeHraLNPoeiU9P yKsfAzOSBpf785eB5kMupns4DDGeCZIlmAOEpJqvhYZ42EPseNCYMaQyo stwDDPY2MK3MsU6jonqVYQiUFhJIfZjmRPJhnjInS5+T01NlOVRTe8b6H mGE7/OFqwlSw2NmhY35g7oK2yenfw8TL1RYW4hplO/7GYtG8Z2aBHWX9U A==; X-CSE-ConnectionGUID: K01A2caMQ4a6QfWAHREz6w== X-CSE-MsgGUID: TRGJT7F9Qy2rYMu4x1Bg1Q== X-IronPort-AV: E=McAfee;i="6700,10204,11177"; a="40849863" X-IronPort-AV: E=Sophos;i="6.10,182,1719903600"; d="scan'208";a="40849863" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by fmvoesa102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Aug 2024 00:51:21 -0700 X-CSE-ConnectionGUID: mV4/iQEoSU2UdekrGE/mQg== X-CSE-MsgGUID: xtm+W/8oToWtEBp4ANQBvg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,182,1719903600"; d="scan'208";a="63133947" Received: from turnipsi.fi.intel.com (HELO kekkonen.fi.intel.com) ([10.237.72.44]) by fmviesa008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Aug 2024 00:51:18 -0700 Received: from kekkonen.localdomain (localhost [127.0.0.1]) by kekkonen.fi.intel.com (Postfix) with SMTP id 1D86911F95D; Wed, 28 Aug 2024 10:51:16 +0300 (EEST) Date: Wed, 28 Aug 2024 07:51:16 +0000 From: Sakari Ailus To: Zhi Mao Cc: Mauro Carvalho Chehab , Matthias Brugger , AngeloGioacchino Del Regno , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, shengnan.wang@mediatek.com, yaya.chang@mediatek.com, teddy.chen@mediatek.com, yunkec@chromium.org, 10572168@qq.com Subject: Re: [PATCH] media: i2c: improve suspend/resume switch performance for GT9769 VCM driver Message-ID: References: <20240817073452.21627-1-zhi.mao@mediatek.com> Precedence: bulk X-Mailing-List: linux-kernel@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: <20240817073452.21627-1-zhi.mao@mediatek.com> Hi Zhi, Thanks for the patch. On Sat, Aug 17, 2024 at 03:34:02PM +0800, Zhi Mao wrote: > GT9769 VCM power-on default setting is PD=0, > so it is not necessary to set again in dw9768_init function, > and it also has no requirement of setting PD=1 > before power-off in dw9768_release function. > For GT9769 VCM, PD mode control will add extra time > when switching between suspend and resume. > e.g. chrome camera AP can switch between video and photo mode, > the behavior corresponding to VCM is suspend and resume, > it will cause camera preview is not smooth. If this is the problem, wouldn't either of these two be a better option: - keep the file handle open in the user space, to avoid powering off the VCM or - add autosuspend support to the driver. I also wouldn't differentiate driver behaviour between the chips. If the hardware default really is different (is it, this is rare for register-compatible parts), then the driver needs to reprogram it (at least on the one with a different default). -- Kind regards, Sakari Ailus