From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 C2A902EA483 for ; Wed, 17 Sep 2025 09:26:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758101203; cv=none; b=Cl3CfuIf7EZAlfqUj6T0evIuh9Ap0rIrMd96nvr6OlUTgOySBaXfB3uP1BQDBe9fza+Uuml4y8VotTZj84TTLjecK3GOkNOTY4Y6PgGYGRpZHHa+icaTmYdmUd3yJgzUG1Gpz7dfZmX/E5xjcB0zEC6CmWLYQ3UQBiFMK3W/g3o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758101203; c=relaxed/simple; bh=IJtYFc3Q9+3XAXBIZkCH7D3WxQhSB0Lo8WibmOq24Hk=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=euWn6PYHmIkTNwakRzWS9PycaSrin/9iyWWPrugl0YdKWT2Q7+c6b1VWvbPelQs+rFRXc1imT4qsrEGBGiqxaToNu2LURdqtsrL0Ray7Te03cgqzwuT6vhMMWRdjT9ZYJaSEW9hDRLNW7cPq3hI395Dqfho6J8F966hMU8m0l/s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ToBCSoRZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ToBCSoRZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 034CFC4CEF0; Wed, 17 Sep 2025 09:26:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758101203; bh=IJtYFc3Q9+3XAXBIZkCH7D3WxQhSB0Lo8WibmOq24Hk=; h=Date:From:To:Cc:Subject:From; b=ToBCSoRZH04+bPsRwZgMRyZ3X//PNPzPLp8YXsXb87ti2HBqE0p+Chg8M3H76aJLM pJEe02YO63DjZRwcWNLLl0P5j+rv21UwRwVjFMs3KoZqpJX4pf6vjkv65Ys3Iv1z/p sW5fP4A/7A0azaHR7Ic/Bu4NoDyYH+kHakBWSZTPXA+O/voyYU+r/kPVR4/btmSOKl if/EP3J9v7H+bZ+RDEzf9Hyypfm4l/wXF6Gngtlyo3oAQ3a4ppY9o0XklxWpbLpfnM KRWHyzEhAS38nBstcWgvpLWU1Z553ZAo1PObOsOKaIYUTQPO92O97iokiObdEY3yA+ 0VCiq24PokdTQ== Date: Wed, 17 Sep 2025 11:26:39 +0200 From: Niklas Cassel To: Thierry Reding , Jonathan Hunter , Vidya Sagar Cc: linux-pci@vger.kernel.org, Shin'ichiro Kawasaki Subject: PCIe tegra194 endpoint mode regulator question Message-ID: Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hello Tegra PCIe maintainers, Looking at the device tree binding for Tegra PCIe endpoint mode: Documentation/devicetree/bindings/pci/nvidia,tegra194-pcie-ep.yaml We can see that 'vddio-pex-ctl-supply' is marked as required. However, when inspecting the driver itself: drivers/pci/controller/dwc/pcie-tegra194.c regulator_enable(pcie->pex_ctl_supply); is only called in tegra_pcie_config_controller(). tegra_pcie_init_controller() is called by tegra_pcie_config_rp() (Root Complex mode), however regulator_enable(pcie->pex_ctl_supply); is never called by tegra_pcie_config_ep() or pex_ep_event_pex_rst_deassert(), or any other function called when the driver is using any of the PCIe endpoint mode compatible strings. So, I think there is something wrong here. Either: 1) 'vddio-pex-ctl-supply' shouldn't be marked as required in the PCIe endpoint mode device tree binding (or perhaps not be there at all, since regulator_enable(pcie->pex_ctl_supply) is never called.) 2) drivers/pci/controller/dwc/pcie-tegra194.c should call regulator_enable(pcie->pex_ctl_supply) even in the endpoint mode case. Looking forward to your feedback. Kind regards, Niklas