From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) (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 F0FFD235045 for ; Sat, 5 Sep 2026 04:38:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.180.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788583120; cv=none; b=eeciE7AF84Bt62R8XOyTiE4qMFchubOW/7njsy/YfHT8DsLDJ3JTpJ90NIpVndkSQgWm5QWKUOn70GPhqzhraw2ZaZJZj70odirjsi+OJR2m3zZIrtCELeSJnqrSp7Tzg/2WBCMPK7zV2bqLHEtJTu9VPRoc+3rNYyioG9uPlrM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788583120; c=relaxed/simple; bh=GSaELF1Z9KjF+xjzZ4dVIBJN17oY05E7ZBJ4GkoS7uQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=c42T5n9dqTXvLx6EwBwV7Vj6whgGWpryxPQ843pTWxbW7p8ONEuZuBfGsVtRp1pW9qHKRPPW819rn2iZgyH9ANvY/S3XDok+16F3izSKmViwxZfkPgUAdl4NhOcjxYAuXcy2I16UJY0mOifW4MdEhsfjvJkUI6x1U5/qkAZWQPo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com; spf=pass smtp.mailfrom=oss.qualcomm.com; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b=bEGHJhMq; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b=Oe8RU5xn; arc=none smtp.client-ip=205.220.180.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b="bEGHJhMq"; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b="Oe8RU5xn" Received: from pps.filterd (m0279870.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 6853PiKF1461796 for ; Sat, 5 Sep 2026 04:38:37 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qualcomm.com; h= cc:content-type:date:from:in-reply-to:message-id:mime-version :references:subject:to; s=qcppdkim1; bh=727iktuEXUXWmmJ7dRTIPHBN 1RZNZgjhTgnKHGSuFFA=; b=bEGHJhMqge7iOVR01D6QrBp8rYhEyHTHhvkjtrkf V4CED43uz5s1IVNgjniKgEuTi3dXtq09xbkK4alAzneoCXPxG903i1l0hJrxA7G0 2xR6y4ZMwsLLO3fl75G3ih7SnEuavdZvBfFMeIvBemwVdQ3bqM+v1P8zHCqCQ4Y4 moVLTlqOnkUyh0CHUSQ+POzYI6ZIOxJ5D7GW5m1ehYNe1SreRq4rBGrrO3Zlsmzq Wau7M7gollCrT9meJR0c5Qoqx6MR+8XX5RaUJiIY78RMYBYyVRvy8gwpKelUWKGu ZsV4akpkIapXhJY8boF8Jvmd/YcAEgAnH/xuR4vqw2MvwA== Received: from mail-pj1-f70.google.com (mail-pj1-f70.google.com [209.85.216.70]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4ggb5v83x3-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Sat, 05 Sep 2026 04:38:37 +0000 (GMT) Received: by mail-pj1-f70.google.com with SMTP id 98e67ed59e1d1-381250979d5so2038662a91.0 for ; Fri, 04 Sep 2026 21:38:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oss.qualcomm.com; s=google; t=1788583117; x=1789187917; darn=vger.kernel.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=727iktuEXUXWmmJ7dRTIPHBN1RZNZgjhTgnKHGSuFFA=; b=Oe8RU5xnmqScSefsubtAmd37M5jYoNnCicvFFYu2lfYaeeNtVfp/4KZ3oJeBhuHreU nNHxqJmGs3TI17fpRJxRfsT5210c2GHXkdLaln8mkddI84huk+9sHyZgSg03ddOGRxzi zegQRdo8P+9KHwNXFmlr9fRKQqAnliQnu8Gah8xvObBULXCQRLzL6kIBwDRDjhJH1Y7n Cy/uqqHDHhwEAzXEhNYH/9B7/Vc6B70ul3ZKAb1FnSQtketmF1mJqLKZyfC4L+F6dy39 Bq9Tye3nFpDIXzSVMUkssRF4VKXGuyWrmoFvN8WUBSxwnbox9ggYU/vpYb8ttX/TtJtY FxBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788583117; x=1789187917; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=727iktuEXUXWmmJ7dRTIPHBN1RZNZgjhTgnKHGSuFFA=; b=KuFwtVliVt6WF86fpTAfYgNmfZ4bEW4pao5dZSjZQQzft4c9wih+lORqufo9Urdip3 XFoGZovcMcwLqRVYfAe6+4OKkoxq5TQjLFMMndXVU2J3/KWL89INwNqSusjJMxw44Ym+ KKww1C1SXPpdW/l4PP2jNn6ZoVGmGk+Bz3V3937hebuq7nE1dCDVAV3vqqvY55T8OPNx P6pPTFXcDET2PmVdMlA5LFxnGPcNceM6pnt3ieDhgcxu6R+YH6XBgUrQNX8UTTl9L5gZ vMpkTNdB1cREUYyx2sG8lOoLNKwXp9cuCoHeWl1Ls7JUOTxtp8VDLwYR0aQOdkwAqwDm NQIA== X-Forwarded-Encrypted: i=1; AKwUvBzC+CQj1hGMoamt2RuAfBC6VdTmAPJ7GJ9SfHwWWo+QC3FErZwN6uQ9D7DrTvE9QbGhUd92d/8TEaKDva8=@vger.kernel.org X-Gm-Message-State: AFuF++mTp2aGzJY+iiz+8NwoEMf+umQ9aAnA7/6twZE61jkomnuOyaK5 0Q4xirnDwaO0cgfOl2mWKr27yKxeIkereqNxMaQxsc67iHdsteG+q03ylAIlD6Ln1AToBFE0bmQ JPJADx2CguYBvyAVBye954bAy0U8hJABZPTcqbIbTVWMvw7Pk4Cz2eKt1565y5RVB3GQ= X-Gm-Gg: AYBFou2J4TUqcq3nfhmR869yGrtQjew2hcakB4Z4AuBnYqgapJpr8IE8ELU+szEIuC2 g0BEIwOifH5oKAoVS1bYnisBvB4x4Prx+nWT0H7GJTSHi7EIHAwqEFFxWGkNJfOuBsZVPgJadhH rPCxmxbHA/X7qSfc9/64WehhAZT/KfdGt0xndcqkZgEhMbZ0Mf/BUxyzBDcmYClEYUzGlC2WWin QSgMjb3W1F/+/nxiqD1qHxbuyXu/s4CgdDmUDjBkr9qLnqGF6yTyExCclbA5frPmItyyCg3+M4g +FtZPk7ibDDUAFzzfHaqf8L7G7rLhiiDc/6nKV4Lm0/7KbAcb5NX2hNMPamlP6Nl9f0t++umHM2 pxAUbgPiO5BBWpClK+0b6greXOnZme1UhkIHV X-Received: by 2002:a17:90b:33c1:b0:398:9bd1:3214 with SMTP id 98e67ed59e1d1-39b262dfa81mr14399909a91.21.1788583116611; Fri, 04 Sep 2026 21:38:36 -0700 (PDT) X-Received: by 2002:a17:90b:33c1:b0:398:9bd1:3214 with SMTP id 98e67ed59e1d1-39b262dfa81mr14399864a91.21.1788583116152; Fri, 04 Sep 2026 21:38:36 -0700 (PDT) Received: from hu-ssmaurya-hyd.qualcomm.com ([202.46.23.25]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-1432423f99fsm10025614c88.1.2026.09.04.21.38.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 04 Sep 2026 21:38:35 -0700 (PDT) Date: Sat, 5 Sep 2026 10:08:30 +0530 From: Shashank Maurya To: Mark Brown Cc: Liam Girdwood , linux-kernel@vger.kernel.org, venkata.valluru@oss.qualcomm.com, Jessica Zhang Subject: Re: [PATCH] regulator: rpi-panel-v2: Add optional vcc-supply support Message-ID: References: <20260828-rpi_reg-v1-1-1066b1f68630@oss.qualcomm.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: X-Proofpoint-ORIG-GUID: GhAEquaBGIX9WkxD5PRG7G1_aGH_jLHZ X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwOTA1MDA0NSBTYWx0ZWRfX0ge8y/KdYAwi Nfob8714WbI4s9xOINNx4JamAGgyZWVQOK+tw3+1PBxLSArF8hoTiUKXYr7RBvKVI8tQ89NWBHu 6iSqaeEFprIKHwawlMYoHzKxVWvKRFfWNhWf3GYdDMtTPD7NbccQOfkYHm+NQhFTS1U3fStJX7g FWSeurbSm/NqJOvPxtNM640wQnpFocKUKpQpgJMZ9CIBRBqIj4QisXhNzHFCUE6D70Y10/0UOHa LMlvhYTUx8i8TYnn1FORibLqc9XLxbn67EeKTjjuUuAnO89XeFSNQbi6Bvp9H+3gGrFi99atDRm Ho1/9VAeFZpqhnNam5NhCbpFswoI1RfEb+pJc+3cr8ZmXf/S3fSheroLqHvMm20bFP99pDbFz0d 9UMFt042IDNMCUJ3dGP7EupLXKgFgGT+3ZIT6k3v3tnxcbkxjBRQKJEjGNbts6OG85f819cSOTk yhP/u7IOqpntoYvgUvg== X-Authority-Analysis: v=2.4 cv=UO3t2ify c=1 sm=1 tr=0 ts=6a9b9ccd cx=c_pps a=0uOsjrqzRL749jD1oC5vDA==:117 a=ZePRamnt/+rB5gQjfz0u9A==:17 a=kj9zAlcOel0A:10 a=VdqzKS8jKosA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=gowsoOTTUOVcmtlkKump:22 a=99y-QX9tk9NJLPcNDyMA:9 a=CjuIK1q_8ugA:10 a=mQ_c8vxmzFEMiUWkPHU9:22 X-Proofpoint-GUID: GhAEquaBGIX9WkxD5PRG7G1_aGH_jLHZ X-Proofpoint-Spam-Info: AW1haW4tMjYwOTA1MDA0NSBTYWx0ZWRfX7iiKCkGvXK2K pyDLP3s928JNS3ZSbXTzYft4r1VItwjexKpVPmQQgByi72PYnzWNVON9OPmWgLLzFqRvsCKFbpG kKAVuCioE+yJPhO2nsG/XpsK/wVrZm4= X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-09-05_01,2026-09-03_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 suspectscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 bulkscore=0 spamscore=0 priorityscore=1501 adultscore=0 phishscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2609050045 On Wed, Sep 02, 2026 at 04:48:33PM +0100, Mark Brown wrote: > On Mon, Aug 31, 2026 at 11:44:08AM +0530, Shashank Maurya wrote: > > On Fri, Aug 28, 2026 at 01:13:42PM +0100, Mark Brown wrote: > > > On Fri, Aug 28, 2026 at 09:59:43AM +0530, Shashank Maurya wrote: > > > > > The Raspberry Pi Panel V2 regulator driver may rely on an external > > > > power rail being provided through the device tree. Add support for an > > > > optional "vcc" regulator and enable it during probe before accessing > > > > the panel controller. > > > > Does the device work without power? A name like "Vcc" makes it sound > > > like this is the main supply for the device... > > > No without VCC, regulator will not be up. So device will not work if > > power rail is software controlled and not always high. > > That doesn't sound very optional then. Apologies I missed below discussion over the list. >> Yes Mark, this isn't optional on qualcomm boards. But it might be optional >> for boards where power up logic is hardware controlled or always high. >That's not how regulators work - with regulators the driver is >independent of the specific system it runs on, the machine constraints >deal with any system specifics. >Please don't take things off-list unless there is a really strong reason >to do so. Sending things to the list ensures that everyone gets a >chance to read and comment on things. Going forward, I'll make vcc sipply compulsory then.