From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0C4FCD2444D for ; Thu, 4 Dec 2025 17:32:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:References:Cc:To:From:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=yWVKxWid5L9rirXdv10wLR3V7TeVNb+lAuR+9tFQfSw=; b=clg/g7cpjYPfPlssfZnQ6m2075 zQs7wWSb4d9IyPQCdd9JqHoqsxddrOONYfc43dVU/67PI5jFJQ6fTlTLPFO720Aj0wqpSUrudxZQD zQVSc0iYI5jVM+mSxsXvI2Z79cyv/TKVkWIJqwJdPFEpHEQ+bCrEsqpNuZ3DdRA9Q3tM33CGFIxdu ixrnSBCi+hEh8AbDorS2pAibeSvPIrhAqtiT9FIx4CdJ3CHujCxKVTvwf7+hSpMp8CtWTr3q5Xl2U RfBqU+UdN1dumVnK14Qk2zoGnJaRX5OQeRUsYYcdbzbK8b4llDCPrDhpCceYDhHXLNio1QNDYzCDS XO2hjKBw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vRDBu-00000008Nix-3IGl; Thu, 04 Dec 2025 17:32:30 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vRDBt-00000008NiR-0LGg; Thu, 04 Dec 2025 17:32:30 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 55B8F43EB4; Thu, 4 Dec 2025 17:32:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D9EC3C4CEFB; Thu, 4 Dec 2025 17:32:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764869548; bh=JSBp6wv2W2X2tHZsp1e5Ojo/YYlzqUJNk/mj18//10I=; h=Date:Subject:From:To:Cc:References:In-Reply-To:From; b=kt2d41PZMO7Ee59B3FD1SP0F+07nXeZBorvhnHTLbeD84SS2Khc0cVg+VUb7kzEmc g/PH2bzO6Zu+x4z/mgtGCxDAsBn9stBt8xd0pUFbA8YMrceGOFVidfE3o7/xuEyVI+ Ifi8e4eJBpDJvHGAoQFKFWNHZPwIQfFzoSRIQaGBzQUEhMFdW+AkOgjS1edjiuW4Du yycDwQ78pWeLgpJJCSleUunGz/g8q7a4+xXohLVn4HAuSzmUx7V0lslUCqhrquiTEa PDEqLnXZar/k/PBcit04JKgnzuCfg8tS+qoNYmiHvx3D9Hr/gStRl5JLc5Q5CG9LXq Z65iEMqgoM3BQ== Message-ID: <9f7da6ae-9e3e-442f-a203-28a8881dbe0f@kernel.org> Date: Thu, 4 Dec 2025 18:32:23 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 2/2] net: dsa: mt7530: Use GPIO polarity to generate correct reset sequence From: Krzysztof Kozlowski To: Vladimir Oltean Cc: Daniel Golle , Frank Wunderlich , Andrew Lunn , Chen Minqiang , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Matthias Brugger , AngeloGioacchino Del Regno , "Chester A. Unal" , DENG Qingfang , Sean Wang , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, netdev@vger.kernel.org References: <0675b35f-217d-4261-9e3f-2eb24753d43c@lunn.ch> <20251130080731.ty2dlxaypxvodxiw@skbuf> <3fbc4e67-b931-421c-9d83-2214aaa2f6ed@lunn.ch> <0d85e1e6-ea75-4f20-aef1-90d446b4bfa1@kernel.org> <00f308a1-a4b1-4f20-8d8e-459ddf4c39b1@gmx.de> <20251204131626.upw77jncqfwxydww@skbuf> <4170c560-1edd-4ff8-96af-a479063be4a5@kernel.org> <20251204160247.yz42mnxvzhxas5jc@skbuf> <66d080f1-e989-451f-9d5e-34460e5eb1b0@kernel.org> <20251204171159.yy3nkvzttxecmhfo@skbuf> <178afbeb-168f-4765-bb0b-fad0bcd29382@kernel.org> Content-Language: en-US Autocrypt: addr=krzk@kernel.org; keydata= xsFNBFVDQq4BEAC6KeLOfFsAvFMBsrCrJ2bCalhPv5+KQF2PS2+iwZI8BpRZoV+Bd5kWvN79 cFgcqTTuNHjAvxtUG8pQgGTHAObYs6xeYJtjUH0ZX6ndJ33FJYf5V3yXqqjcZ30FgHzJCFUu JMp7PSyMPzpUXfU12yfcRYVEMQrmplNZssmYhiTeVicuOOypWugZKVLGNm0IweVCaZ/DJDIH gNbpvVwjcKYrx85m9cBVEBUGaQP6AT7qlVCkrf50v8bofSIyVa2xmubbAwwFA1oxoOusjPIE J3iadrwpFvsZjF5uHAKS+7wHLoW9hVzOnLbX6ajk5Hf8Pb1m+VH/E8bPBNNYKkfTtypTDUCj NYcd27tjnXfG+SDs/EXNUAIRefCyvaRG7oRYF3Ec+2RgQDRnmmjCjoQNbFrJvJkFHlPeHaeS BosGY+XWKydnmsfY7SSnjAzLUGAFhLd/XDVpb1Een2XucPpKvt9ORF+48gy12FA5GduRLhQU vK4tU7ojoem/G23PcowM1CwPurC8sAVsQb9KmwTGh7rVz3ks3w/zfGBy3+WmLg++C2Wct6nM Pd8/6CBVjEWqD06/RjI2AnjIq5fSEH/BIfXXfC68nMp9BZoy3So4ZsbOlBmtAPvMYX6U8VwD TNeBxJu5Ex0Izf1NV9CzC3nNaFUYOY8KfN01X5SExAoVTr09ewARAQABzSVLcnp5c3p0b2Yg S296bG93c2tpIDxrcnprQGtlcm5lbC5vcmc+wsGVBBMBCgA/AhsDBgsJCAcDAgYVCAIJCgsE FgIDAQIeAQIXgBYhBJvQfg4MUfjVlne3VBuTQ307QWKbBQJoF1BKBQkWlnSaAAoJEBuTQ307 QWKbHukP/3t4tRp/bvDnxJfmNdNVn0gv9ep3L39IntPalBFwRKytqeQkzAju0whYWg+R/rwp +r2I1Fzwt7+PTjsnMFlh1AZxGDmP5MFkzVsMnfX1lGiXhYSOMP97XL6R1QSXxaWOpGNCDaUl ajorB0lJDcC0q3xAdwzRConxYVhlgmTrRiD8oLlSCD5baEAt5Zw17UTNDnDGmZQKR0fqLpWy 786Lm5OScb7DjEgcA2PRm17st4UQ1kF0rQHokVaotxRM74PPDB8bCsunlghJl1DRK9s1aSuN hL1Pv9VD8b4dFNvCo7b4hfAANPU67W40AaaGZ3UAfmw+1MYyo4QuAZGKzaP2ukbdCD/DYnqi tJy88XqWtyb4UQWKNoQqGKzlYXdKsldYqrLHGoMvj1UN9XcRtXHST/IaLn72o7j7/h/Ac5EL 8lSUVIG4TYn59NyxxAXa07Wi6zjVL1U11fTnFmE29ALYQEXKBI3KUO1A3p4sQWzU7uRmbuxn naUmm8RbpMcOfa9JjlXCLmQ5IP7Rr5tYZUCkZz08LIfF8UMXwH7OOEX87Y++EkAB+pzKZNNd hwoXulTAgjSy+OiaLtuCys9VdXLZ3Zy314azaCU3BoWgaMV0eAW/+gprWMXQM1lrlzvwlD/k whyy9wGf0AEPpLssLVt9VVxNjo6BIkt6d1pMg6mHsUEVzsFNBFVDXDQBEADNkrQYSREUL4D3 Gws46JEoZ9HEQOKtkrwjrzlw/tCmqVzERRPvz2Xg8n7+HRCrgqnodIYoUh5WsU84N03KlLue MNsWLJBvBaubYN4JuJIdRr4dS4oyF1/fQAQPHh8Thpiz0SAZFx6iWKB7Qrz3OrGCjTPcW6ei OMheesVS5hxietSmlin+SilmIAPZHx7n242u6kdHOh+/SyLImKn/dh9RzatVpUKbv34eP1wA GldWsRxbf3WP9pFNObSzI/Bo3kA89Xx2rO2roC+Gq4LeHvo7ptzcLcrqaHUAcZ3CgFG88CnA 6z6lBZn0WyewEcPOPdcUB2Q7D/NiUY+HDiV99rAYPJztjeTrBSTnHeSBPb+qn5ZZGQwIdUW9 YegxWKvXXHTwB5eMzo/RB6vffwqcnHDoe0q7VgzRRZJwpi6aMIXLfeWZ5Wrwaw2zldFuO4Dt 91pFzBSOIpeMtfgb/Pfe/a1WJ/GgaIRIBE+NUqckM+3zJHGmVPqJP/h2Iwv6nw8U+7Yyl6gU BLHFTg2hYnLFJI4Xjg+AX1hHFVKmvl3VBHIsBv0oDcsQWXqY+NaFahT0lRPjYtrTa1v3tem/ JoFzZ4B0p27K+qQCF2R96hVvuEyjzBmdq2esyE6zIqftdo4MOJho8uctOiWbwNNq2U9pPWmu 4vXVFBYIGmpyNPYzRm0QPwARAQABwsF8BBgBCgAmAhsMFiEEm9B+DgxR+NWWd7dUG5NDfTtB YpsFAmgXUF8FCRaWWyoACgkQG5NDfTtBYptO0w//dlXJs5/42hAXKsk+PDg3wyEFb4NpyA1v qmx7SfAzk9Hf6lWwU1O6AbqNMbh6PjEwadKUk1m04S7EjdQLsj/MBSgoQtCT3MDmWUUtHZd5 RYIPnPq3WVB47GtuO6/u375tsxhtf7vt95QSYJwCB+ZUgo4T+FV4hquZ4AsRkbgavtIzQisg Dgv76tnEv3YHV8Jn9mi/Bu0FURF+5kpdMfgo1sq6RXNQ//TVf8yFgRtTUdXxW/qHjlYURrm2 H4kutobVEIxiyu6m05q3e9eZB/TaMMNVORx+1kM3j7f0rwtEYUFzY1ygQfpcMDPl7pRYoJjB dSsm0ZuzDaCwaxg2t8hqQJBzJCezTOIkjHUsWAK+tEbU4Z4SnNpCyM3fBqsgYdJxjyC/tWVT AQ18NRLtPw7tK1rdcwCl0GFQHwSwk5pDpz1NH40e6lU+NcXSeiqkDDRkHlftKPV/dV+lQXiu jWt87ecuHlpL3uuQ0ZZNWqHgZoQLXoqC2ZV5KrtKWb/jyiFX/sxSrodALf0zf+tfHv0FZWT2 zHjUqd0t4njD/UOsuIMOQn4Ig0SdivYPfZukb5cdasKJukG1NOpbW7yRNivaCnfZz6dTawXw XRIV/KDsHQiyVxKvN73bThKhONkcX2LWuD928tAR6XMM2G5ovxLe09vuOzzfTWQDsm++9UKF a/A= In-Reply-To: <178afbeb-168f-4765-bb0b-fad0bcd29382@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251204_093229_167007_AFA5468F X-CRM114-Status: GOOD ( 16.60 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 04/12/2025 18:23, Krzysztof Kozlowski wrote: > On 04/12/2025 18:11, Vladimir Oltean wrote: >> On Thu, Dec 04, 2025 at 05:48:07PM +0100, Krzysztof Kozlowski wrote: >>> Both are the same - inverter or NOT gate, same stuff. It is just >>> connecting wire to pull up, not actual component on the board (although >>> one could make and buy such component as well...). We never describe >>> these inverters in the DTS, these are just too trivial circuits, thus >>> the final GPIO_ACTIVE_XXX should already include whatever is on the wire >>> between SoC and device. >> >> Please read what Andrew said: >> https://lore.kernel.org/netdev/3fbc4e67-b931-421c-9d83-2214aaa2f6ed@lunn.ch/ >> >> Assuming there is not a NOT gate placed between the GPIO and the reset >> pin, because the board designer decided to do that for some reason? >> ~~~~~~~~~~~~~~ >> >> You two are *not* talking about the same thing. I dismissed the > > > It's the same thing. NOT gate is just pulling some pin down or up. Although transistor would be still needed, so indeed that's still a bit more than a wire and resistor as I implied. It looks like: https://www.electronics-tutorials.ws/wp-content/uploads/2018/05/logic-log47.gif > >> probability of there being a NOT gate in the form of a discrete chip on > > We do not describe NOT gates as discreet chips. I don't think anyone > actually places something as NOT gate. It's logical NOT gate, but on > circuit it is just pull up/down as I said multiple times. The pull + > resistor is the "NOT gate". > > It's so easy and that's why it is potentially so common design. We still do not describe transistors in DTS. We do not describe NOT gates. The final flag should include that as I said. Best regards, Krzysztof