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 68D142FC025; Tue, 14 Oct 2025 14:06:52 +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=1760450812; cv=none; b=PgA2W6q8QkZHJc2+TFHzQXQ52q4Aqk4f2oDcD0ddgAGe4+jt0qh8EPwu6Y99DWFBebAMcX22ERuoPaXq0W7JdkDOU0auY/k7W5mXQ+CGruWYNldYIm5l9ELZfoWcJIEj2ECBeLRdttQd08iPb/NrBAZ+y4eEUMUYpbe32g8IGh4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760450812; c=relaxed/simple; bh=w9tTYK2yli0RK86hTbg570XA47pgHGHINBubz7rRa3w=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=RYcFjq/iiMB75gBKbC0k3djk9kXisRqIeIwZdWstBs4G+GHjpr3WaJM2/opSW+mgvy+ce8LSQbG+sjcZ/78ZEgj619frrOoMkuduueM67O+0NqowE3roaFIlrzxNSnGtSgRJKBPeS8v7oI0Bkz5RnQ2Xg5Pikt3NSPtflZ9oxlY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kZ3bIbbD; 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="kZ3bIbbD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B2AF6C4CEE7; Tue, 14 Oct 2025 14:06:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760450812; bh=w9tTYK2yli0RK86hTbg570XA47pgHGHINBubz7rRa3w=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kZ3bIbbD6nkd8W5IVl3HfDuXGYs7srO4U+jUj9+dg4aSt9J09mf3p5rJt2Glt/f65 Hp8a7NXoAqk2em8EMdr97Qwl4aHuQWqfZUr6hxhxo18XeT4SRYY/rxBVfoIfXLFLkp +pKhSeXVzAdQgyYeZL3hgmICo1pGE2KnIVG17TyFz6s45/Qd0ZLc0cESsQeBJwpS+W srItru5EHM3Hk2PAdFv6DUARb3hjEJIVtOQFXyYAp/lI05LZy9sKZ/XFiwFQQ5Xqpn pgEWN7NzMUISgvc8sLQ+7ZOjQEqnJR+GU/VDtsIaBIptoGNqq6jZ9V2EeFctPyaQjp uvQ3TX7WlZNVw== Date: Tue, 14 Oct 2025 15:06:47 +0100 From: Simon Horman To: Kory Maincent Cc: Oleksij Rempel , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Thomas Petazzoni , kernel@pengutronix.de, Dent Project , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next v2 3/3] net: pse-pd: pd692x0: Preserve PSE configuration across reboots Message-ID: References: <20251013-feature_pd692x0_reboot_keep_conf-v2-0-68ab082a93dd@bootlin.com> <20251013-feature_pd692x0_reboot_keep_conf-v2-3-68ab082a93dd@bootlin.com> <20251014115659.0e6fd10c@kmaincent-XPS-13-7390> Precedence: bulk X-Mailing-List: netdev@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: <20251014115659.0e6fd10c@kmaincent-XPS-13-7390> On Tue, Oct 14, 2025 at 11:56:59AM +0200, Kory Maincent wrote: > On Tue, 14 Oct 2025 09:58:56 +0100 > Simon Horman wrote: > > > On Mon, Oct 13, 2025 at 04:05:33PM +0200, Kory Maincent wrote: > > > From: Kory Maincent (Dent Project) > > > > > > Detect when PSE hardware is already configured (user byte == 42) and > > > skip hardware initialization to prevent power interruption to connected > > > devices during system reboots. > > > > > > Previously, the driver would always reconfigure the PSE hardware on > > > probe, causing a port matrix reflash that resulted in temporary power > > > loss to all connected devices. This change maintains power continuity > > > by preserving existing configuration when the PSE has been previously > > > initialized. > > > > > > Signed-off-by: Kory Maincent > > > > Hi Kory, > > > > Perhaps I'm over thinking things here. But I'm wondering > > what provision there is for a situation whereby: > > > > 1. The driver configures the device > > 2. A reboot occurs > > 2. The (updated) driver wants to (re)configure the device > > with a different configuration, say because it turns > > out there was a bug in or enhancement to the procedure at 1. > > > > ... > > You have to find a way to turn off the power supply of the PSE > controller. As adding a devlink uAPI for this was not accepted, a hard > reset for the PSE controller is the only way to clean the user byte > register and (re)configure the controller at boot time. Ok, as long as there is a way. Maybe worth mentioning in the commit message. But either way this patch looks good to me. Reviewed-by: Simon Horman