From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.20]) (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 A46423168F1; Fri, 23 Jan 2026 07:21:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.20 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769152870; cv=none; b=jiLjqGise7k4AjWu8OQBzGvG8etwsnEsESS8VT9KV6Yrac7Ek3zEScYBSJNkfnvSm2rU8kB6CZzkUA0cr2pIw8hZJcaCfDA2H+tqxIXKzQVG5D/nlYlXynBFhJobDivI1vF9eB5WNGqnEo1KSIKVnHA5yrUeGxoNd5jvLK+FtTU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769152870; c=relaxed/simple; bh=EVZM8i72JTVmyCAaYpKZOevQq4ai7P5rZPslFXeTKZI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=N6Vvvf8drM5kqfUI0FUXXZsGSLCaFnzVM5YZdydmKon5U5ODE/YIILXisM06ekVRaNVbFTF50Si76Vte2rq7sR2CIImGQjPQJo09F0e0Ze/Bm94Z1bbifthUzD4dehDw4MxqtWPm3ULJ2yyzbC2KgKvzWrh+7ZFt0+fpRz0oU/A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=XwXkInno; arc=none smtp.client-ip=198.175.65.20 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="XwXkInno" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1769152869; x=1800688869; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=EVZM8i72JTVmyCAaYpKZOevQq4ai7P5rZPslFXeTKZI=; b=XwXkInnoXLfo5GXOeSixoInXS898wbRXRmVe5YIFy3wNxw9xUiJZU1sV w6EZajZgT4rmP8JbrwLpW8xOQZ52cHhshWm0yosEs6QqAz6fB+rY498c9 q2ygEAOnlApFZBMiUOHeAoX5d3H4jVn5Js0u7+WqA8MTuBoXtSqjkLPms rZk3w8mst10NvZco+wIxuZRfE+vWPnBaDlC2w9mZZog8KusZkg9Un23Rz C/wEEc0Q7N9snphKQDqwI3ixtTV/b5zPhDCfZ5czhtvueu2NLWR591GFb RRP8UY3CnLM1P0LjeUjmA/KoLRKZxVnsyqT8kRQiGAoqbC+FpjjF6aNvX w==; X-CSE-ConnectionGUID: s3J3/VHZTuyJ6O6w7fnqow== X-CSE-MsgGUID: /hA74zfNQwaWrNeypbVCEg== X-IronPort-AV: E=McAfee;i="6800,10657,11679"; a="70125915" X-IronPort-AV: E=Sophos;i="6.21,248,1763452800"; d="scan'208";a="70125915" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jan 2026 23:21:06 -0800 X-CSE-ConnectionGUID: adBIYdryTta+8/J/CZNT0Q== X-CSE-MsgGUID: hboqfqoRR0ySr41HzLAWrA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,248,1763452800"; d="scan'208";a="207005243" Received: from rvuia-mobl.ger.corp.intel.com (HELO localhost) ([10.245.244.112]) by orviesa007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jan 2026 23:21:01 -0800 Date: Fri, 23 Jan 2026 09:20:58 +0200 From: Andy Shevchenko To: Vladimir Oltean Cc: netdev@vger.kernel.org, Andrew Lunn , Heiner Kallweit , Russell King , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , linux-kernel@vger.kernel.org, Herve Codina , Mark Brown , Serge Semin , Maxime Chevallier , Lee Jones , Rob Herring , Krzysztof Kozlowski , Conor Dooley , devicetree@vger.kernel.org, Jiawen Wu Subject: Re: [PATCH v2 net-next 01/15] net: mdio-regmap: permit working with non-MMIO regmaps Message-ID: References: <20260122105654.105600-1-vladimir.oltean@nxp.com> <20260122105654.105600-2-vladimir.oltean@nxp.com> <20260122121301.cyxyevi7xvqw2axk@skbuf> <20260122134704.pxeikyk4q7nhay55@skbuf> <20260122221848.py4p7mwxzybicnsq@skbuf> 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: <20260122221848.py4p7mwxzybicnsq@skbuf> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Fri, Jan 23, 2026 at 12:18:48AM +0200, Vladimir Oltean wrote: > On Thu, Jan 22, 2026 at 04:38:37PM +0200, Andy Shevchenko wrote: > > On Thu, Jan 22, 2026 at 03:47:04PM +0200, Vladimir Oltean wrote: > > > On Thu, Jan 22, 2026 at 02:13:01PM +0200, Vladimir Oltean wrote: ... > > > > > > + unsigned int base; > > > > > > > > > > Hmm... resource_size_t ? > > > > > > Well, regmap_read() takes "unsigned int reg". > > > > https://elixir.bootlin.com/linux/v6.18.6/source/include/linux/regmap.h#L1297 > > > > So in practice, a truncation will be done somewhere if the register base > > > > exceeds unsigned int storage capacity. But I didn't feel that it's worth > > > > handling that. > > > > > > Would this address your feedback? > > > > Yes and no. See my remarks below. ... > > > - if (config->resource) > > > + if (config->resource) { > > > > Btw, this might be not enough, one should check size and flags as well > > before use. There was a discussion about this recently. Maybe we should > > just move to a simple unsigned int in the config for now? Because handling > > resources maybe considered as over engineering in this case. > > The resource flags are never taken into consideration, but I can for > sure replace the resource in struct mdio_regmap_config with just an > unsigned int start and an end, but that doesn't get rid of the resource > usage. The dev_get_resource(dev->parent, NULL) call is how we learn of > where our register window is located in the "one big regmap" provided by > the parent (SJA1105). So we still need this check somewhere else if we > wanted to not fail silently in case of address bits truncation. Hmm... Bu why we can't embed the full struct resource in such a case? Because resource should have a flag check, otherwise it's a wrong check. Discussion I mentioned is this: https://lore.kernel.org/lkml/20251207215359.28895-1-ansuelsmth@gmail.com/ Fixes due to that finding: https://lore.kernel.org/lkml/20251208200437.14199-1-ansuelsmth@gmail.com/ https://lore.kernel.org/lkml/20251208145654.5294-1-ilpo.jarvinen@linux.intel.com/ > > > + if (config->resource->start > U32_MAX || > > > + config->resource->end > U32_MAX) { > > > > Ideally it should be resource_overlaps() check. But see above. > > resource_overlaps_with_what? The only problem is that the resource can > exceed the 32 bit representation that regmap works with. Obviously with the 4G address space :-) struct resource r4g = DEFINE_RESOURCE...(..., 0, SZ_4G...); if (resource_overlaps(&r4g, config->resource)) aiaiai! // using %pR to print the content > > > + dev_err(config->parent, > > > + "Resource exceeds regmap API addressing possibilities\n"); > > > + return ERR_PTR(-EINVAL); > > > + } > > > mr->base = config->resource->start; > > > + } -- With Best Regards, Andy Shevchenko