From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=194.117.254.33 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794306276; b=srjxwsHE7ShSoD/MsRa3WHTE9dCq5V7T7ySX2TC/u3mCg5Yowdu3aCPNPz7FEaSZ+pEJ OGbM330undCRQdc1R/V90rLfcLLJUVE9tjiBjoEL7q0L+XH32EgQsWglf4WUQl80ovgYF /3gNNAK3eZbgQvF0TO2bs8zE9jVExZ495f+TfUmNE1nR5C928A7AtuPIykIL87hrMyx35 rar8KzzMwearPSbMerEUTijKk9EMBAE9Z7ze5mt9LAlfLyVlR7icZDiDQHXZ1TIyRo5Hr X+WTdfA0Uek6wjrCeX8UyjySBvuI6HXYJ2Lkm+nM2FWXH7Zw9NVHbpYQRvw5RFrUquw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794306276; h=DMARC-Filter:DKIM-Signature:Received:Received:X-UD-Smtp-Session:Date: From:To:Cc:Subject:Message-ID:References:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; bh=0k92K8b49X9cIdh2GF82mc+d2Q8OVuyS6TzYE36ZPtE=; b=exoEoc/ZXROMasmbrsvvitnXBXk/vUMyxWj5FsqP4froYFToLbb6scevVpxt8NzsINCS qdZyqsffmzMNWW11lgJmuq25mPvNi9Xh8A3iia8kCprDLwd4BjFzwRe5Ez+T05kqUrkjy OA4/+tYLKPM4qjLF4Ayu5oDG45cS5oT5yL4aUfehfCG2N6/kq1hcUcH8DIxlS1KE2AeaR DwY11UfoOg5jEfyDTPNuuYa1BwTEC88Ici3KhmSvCqllmqt3+AvyIdWXVGOtXLPpHP4WN UPvn5qpyU6U4y5u7Q0Talmh4r5hdlCm7P+kCCdYe87cxe6jRMlqjej6mn1HLWqgzShw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none header.from=sang-engineering.com; spf=pass smtp.mailfrom=sang-engineering.com; dkim=pass header.d=sang-engineering.com header.i=@sang-engineering.com header.a=rsa-sha256 header.s=k1 header.b=CixjJzFD; arc=none smtp.remote-ip=194.117.254.33 Received: from mail.zeus03.de (zeus03.de [194.117.254.33]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8D807606B993 for ; Tue, 10 Nov 2026 10:24:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 8D807606B993 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sang-engineering.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sang-engineering.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=sang-engineering.com header.i=@sang-engineering.com header.a=rsa-sha256 header.s=k1 header.b=CixjJzFD DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= sang-engineering.com; h=date:from:to:cc:subject:message-id :references:mime-version:content-type:in-reply-to; s=k1; bh=0k92 K8b49X9cIdh2GF82mc+d2Q8OVuyS6TzYE36ZPtE=; b=CixjJzFDIKVpJGj+e0HN K1hHUYCLcVXcQKua5AIHTqIEXd5XLR2K1xiTJiW2GZNBtgbADz+FWMM9nZCm5O2A ZuOK98Piur0oC5bOuegmdwsw69YpeqRvB7bwO92tbfcETkfdXVUD92zjWf6oteO6 XKkCKkyuLtfqXlmZriJXEm7hdU9Iyuw3nI7V9OP/3t/+WHRZG95vERR+3slbMEg+ a0OOYfzzjZax/bZsoodgw4a8unf3OW/TkvCAUmHGjZKm8h5uvQ1C9b2Qe8gikhna 7D9iw2niRkO5MQh3Xk8tUGLp562kgtB84GdmAOkIZkeIxxtr+6Gaj4Gt84AXxuPH gg== Received: (qmail 187841 invoked from network); 10 Nov 2026 11:24:25 +0100 Received: by mail.zeus03.de with ESMTPSA (TLS_AES_256_GCM_SHA384 encrypted, authenticated); 10 Nov 2026 11:24:25 +0100 X-UD-Smtp-Session: l3s3148p1@rcKKe+lfZuoujnsO Date: Tue, 10 Nov 2026 11:24:24 +0100 From: Wolfram Sang To: Chen-Yu Tsai Cc: Mark Brown , Matthias Brugger , AngeloGioacchino Del Regno , Dmitry Torokhov , Jiri Kosina , Andi Shyti , Benson Leung , Tzung-Bi Shih , linux-mediatek@lists.infradead.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, chrome-platform@lists.linux.dev, linux-input@vger.kernel.org, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v7 4/8] i2c: of-prober: skip post-power-on delay if powered on sufficiently long Message-ID: References: <20261103043734.2179858-1-wenst@chromium.org> <20261103043734.2179858-5-wenst@chromium.org> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261103043734.2179858-5-wenst@chromium.org> On Tue, Nov 03, 2026 at 12:37:28PM +0800, Chen-Yu Tsai wrote: > On some devices the I2C component is powered from an always-on power > rail, or the power rail has been left on by either POR defaults or > the bootloader. By the time the prober probes the device, the device > most certainly has finished initializing and can respond. There is no > need for the delay. > > In such designs, the system integrators tend to work around the delay > to avoid the boot time penalty by simply omitting it from the device > tree and the component prober. This is undesired, as the device tree > is not fully describing the hardware. > > Switch to the new regulator_enable_and_wait() function that makes sure > a certain amount of time has passed since the regulator supply was > actually enabled. > > Signed-off-by: Chen-Yu Tsai Acked-by: Wolfram Sang @Andi: Chen-Yu is the maintainer of the of-prober, so I suggest these changes just go in together with this series.