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 44A2E331A75; Thu, 20 Nov 2025 15:51:22 +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=1763653883; cv=none; b=rsSJlQVaWIw6G6ibKOY2thrTgLlusyPvR9/z6jKEJwJHdI0xmW3/333blTifjOPex56eSQCjXcagse1DcAwUiZ4/YPeKDbirgidFUvVXPBS8lbYNck9fi7lZ3E0M2odsM2t+LFVPpEe0SP/Nd1PkzsTnsoQn++I/pbYJX0pEwqA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763653883; c=relaxed/simple; bh=fIBZ6q3XFCpvVgyydIBarvlMB2V8B4BI0n8ooIoqs7c=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=gWl/MqgKnU/yg1LCC1wU96PusUq9X0jnrllMtqEp1va/0nKpNpx7/dOLlzp5zJTuwSntvH6Bag2yVkiSSJ8nm+kak5OJdHSemjoYv61iijq7pFYg2LDRfN5ReaXQZKPcC6q+/iwIUfhX+a/PMKkcIc8Fp77zXn7zA+kf0TMruTA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pVdlcp20; 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="pVdlcp20" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BBF0DC4CEF1; Thu, 20 Nov 2025 15:51:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763653882; bh=fIBZ6q3XFCpvVgyydIBarvlMB2V8B4BI0n8ooIoqs7c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pVdlcp20M/Y/6fnfRkHoyCfCacPwy0V5wiwAuqHvg+RKigbE3xok1/qFUSTVaG00E Jgv2JULNlypEahNuX2hh4+cxwfbKDdKGDwRWt4QFJn/Te4Fbv4CyyTFy/PjgnFrHxc Dn/rLw4VOZYkyf4FdV+yHPM2GfBer/10P1U43xbam3kJQB52QW3LZAwXnegT3wIB6P TpENTKYNvC0UeN65YaIKTXG6RfDmxRBofCTI9/9CeEF9TNdCnKDR4tzXi0MkVDSmJd ytD8AQr6wHWKXWqvxSA9z9t/kBO2ZpsVM+F4elirZ32+9EkXz9uzXb558dv4HaGBTz qMTnhETD6o23A== Received: from johan by xi.lan with local (Exim 4.98.2) (envelope-from ) id 1vM6wM-000000005wH-1bvk; Thu, 20 Nov 2025 16:51:23 +0100 Date: Thu, 20 Nov 2025 16:51:22 +0100 From: Johan Hovold To: alejandroe1@geotab.com Cc: Rob Herring , Krzysztof Kozlowski , Conor Dooley , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Krzysztof Kozlowski Subject: Re: [PATCH v3 2/2] gnss: ubx: add support for the safeboot gpio Message-ID: References: <20250911-ubx-safeboot-v3-0-32fe6b882a3c@geotab.com> <20250911-ubx-safeboot-v3-2-32fe6b882a3c@geotab.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: On Fri, Nov 14, 2025 at 03:59:24PM +0100, Johan Hovold wrote: > On Thu, Sep 11, 2025 at 02:58:29PM +0200, Alejandro Enrique via B4 Relay wrote: > > From: Alejandro Enrique > > > > U-Blox 8/M8/M9 chip have a pin to start it in safeboot mode, to be > > used to recover from situations where the flash content has become > > corrupted and needs to be restored. If this pin is asserted at power > > up/reset, the receiver starts in safeboot mode and GNSS operation is > > disabled. > > > > Deassert the safeboot pin when probing this driver. > Note however that both the RESET_N and SAFEBOOT_N pins should be > declared as open-drain to avoid driving them while the main supply is > off. > > I added a comment about this to the commit message about this when > applying and will send a follow-on patch to update the binding example. I was playing with the idea of adding a warning about this to the driver when realised that there would typically be a level shifter for these signals that makes sure they are not driven while the supply is off so I dropped the comment instead. Johan