From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f178.google.com (mail-pl1-f178.google.com [209.85.214.178]) (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 E52433C5539 for ; Tue, 28 Jul 2026 20:03:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785269000; cv=none; b=GuA0e+ZMNb9NyUxPVNGHEQ8EXqplxWImTkXI4LwNnKSOrrnJv4Ra5VzuWCL66baYHO8cG8j7ixuI0ZloQDpw+Q7M58u/1cvWKgP+4HUlwthXTvS0gIUauu+NkNud3lsvj2TxCilA1v9BQJbUOcjb060XScKYWSdXDf7puUKIT+c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785269000; c=relaxed/simple; bh=9iNjrrVtL3NNUry5XR4/x0JtSnWNg24S//oMYnqZvp4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SJTh8dsikVud4pRuJu91GRe/B03B/RpBFBB9mf61XR1zD2lyRNyoO4ThNtQhRvdj7Bzqv13dW0uHB/KwjDZZryqWeb3xcWSXhnbpBILHXQV4Tj8BjC3jdju0uSlWYpaDN640+J6w9DFgdP56EgfNcQLfzY/aWmA9fPa5G9G5dwI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=maticrobots.com; spf=pass smtp.mailfrom=matician.com; dkim=pass (2048-bit key) header.d=maticrobots.com header.i=@maticrobots.com header.b=XC++u4ph; arc=none smtp.client-ip=209.85.214.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=maticrobots.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=matician.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=maticrobots.com header.i=@maticrobots.com header.b="XC++u4ph" Received: by mail-pl1-f178.google.com with SMTP id d9443c01a7336-2caced6038eso2954685ad.0 for ; Tue, 28 Jul 2026 13:03:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=maticrobots.com; s=google; t=1785268998; x=1785873798; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=9iNjrrVtL3NNUry5XR4/x0JtSnWNg24S//oMYnqZvp4=; b=XC++u4ph5xROyX+DsNdnzheTuXpUDCte7rAz/p++3I3ts4C1AAtQ42cbu1bP24gHTS P2Ds0aDpTmzekYrMCn4u1PpatJikfYCIAh9X57IfD+ufQ3T3My1CTICNq6K3MdZhu9fV sfeXJRfnBwQchTdRKiiYmR7X5RR4jZ9TfEVARgBwHn42F5RjNfhI8xLSYj1q2q7M6Oow a2KoXZwz1i4TyBEaHNY6pO3RdafHp2ewopJOqdm05/n+CGQn6Ovnn7LPi7AWBCbBYm6U 1NWYt5kWlwsRZHn5cUjN5MSn5N3TerDPYpRFdce52pfuW+0FYES6ElQz6CpKs09haFXR 1l1w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785268998; x=1785873798; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=9iNjrrVtL3NNUry5XR4/x0JtSnWNg24S//oMYnqZvp4=; b=YFbKV72vqcsOkw0p0rB2RknIKfXRBDB666ZpCQQWDfrAY7X6KEme34ZtiIlWo/w+JR aa5F3zlItrJx9cRmE8oVNRb0UWwwhDdT1xUQBJlezfJH+T1y5wrz62rC5DwHqok0YvVc l+1hZgqCeBYzv+1m71XlZ1zjsI2y05/DqxaOzpfUUMpJnvAiAUGRk0RLi5v0/U3tOmgO DsnKybkJJA2350IRtXPb0gw0Q01UagqJlVCbDpoSVCh9zGEZqQjhqYQbpOZUXxfOHDRd LFWsWefBiiJkiVos0qhIAC2+xQ9AorMyYm2h43FDgMMl3CGzXDEYunsDS/ufRMMmBeSn LIjQ== X-Forwarded-Encrypted: i=1; AHgh+RpvYbzfc696gGLL7Z/Ih20TrCixZeafkE3xOQJu5w+nlrZSHfQGnPAt1FvbqCe6GyUismGjkeqEGLGRbxs=@vger.kernel.org X-Gm-Message-State: AOJu0Yx89JGmzlkqE1H6oYkSSeNdPqkJ0iz2sSUsQfDhbjZzM8yH1KhA xpm/eGtwARyTG5pLUnQn+QSFe2OAe9D83GKVHLvWo6+ZR7QXRO1BXHe0pvaGPesJXE0PUwID+aq nwLV6RTDRGA== X-Gm-Gg: AR+sD11CCoPKejHSCeC/c6uXaS+7scaPG8CQlz0QkImG4RSzrYvrmRKSDgO79AxQ5I3 UMY/3x5u3UCXZHxrZFp5Jtp5miQmRWIjrQYrQu7/V0zlthLusTNCamnama4c1OkSKmDw5L5Qqsr MMNZlySqLlQNG2d4jm9zWgyfG53HbTwQh5qEucJmnOiEA30ujyOta6D+SLolJsWES4oFRjVuPAv WS5I/fOi+2dLGfakKGa+5ptEXXsDch6yMwOfxVi92j0d292JK0GuadNeXkGinLV7oyoRMN8H6gs x/1lOUbvFH3MSaYORp+wufHN0XOiopztEh8ALAdSau5tbhsN3fZB1nUhJhDInCMm756LEIk/mmj 5Sa4rBgjsfm2A4MNCrnf6tC2+EPRPn+Y8vch5VEOHabtJSgNyIW0EEywcyoZS5itEOTfqHXkNBc D+MITWDbLWKvB9UYbbsCinw+dzo1xRhd8YGPFQisV8alMo3HX4UgJjAmnVhNaPW2IggPijkKmYT SGcAadfx6KdIGSrmvDq/MtrBKxi91bRA3be0A== X-Received: by 2002:a17:903:41cf:b0:2cf:4c37:d955 with SMTP id d9443c01a7336-2d015f082famr40755285ad.27.1785268998323; Tue, 28 Jul 2026 13:03:18 -0700 (PDT) Received: from abeMaticDesktop.1020marsh.offices.matician.com ([2600:1700:471:807f:68c8:458c:c1f7:4115]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-31504b125bbsm1810890eec.5.2026.07.28.13.03.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Jul 2026 13:03:17 -0700 (PDT) From: Abraham Zukor To: Jon Hunter , Mark Brown , Laxman Dewangan Cc: Thierry Reding , linux-spi@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] spi: tegra114: initialize native chip selects inactive Date: Tue, 28 Jul 2026 13:03:12 -0700 Message-ID: <20260728200316.1363536-1-abe@maticrobots.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <9c196ab1-1945-49fc-a89a-5588d1e50046@nvidia.com> References: <20260725042944.1204409-1-abe@maticrobots.com> <20260728025503.162543-1-abe@maticrobots.com> <9c196ab1-1945-49fc-a89a-5588d1e50046@nvidia.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7bit On 28/07/2026 10:34, Jon Hunter wrote: > Exactly. That's my point. Which is the right one? The answer is > probably neither, but whatever is present on the bus. I think that defaulting to active-low is correct. The Tegra234 SPI controller hardware defaults to active-low (all bits in CS_POL_INACTIVE are set) so an active-high device is already asserted before this driver initializes. I checked the controller drivers under drivers/spi/; they either default to active-low or preserve the hardware default. A more complex option is to scan the device tree children, check each item for whether it uses native chip select (as opposed to GPIO CS) and check for spi-cs-high. I found no other spi drivers that do this at probe time, and I don't think it's worth the complexity, but I can send it as a v2 if needed. Thanks, Abe