From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.9]) (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 2A918187860; Mon, 29 Jul 2024 14:28:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.9 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722263326; cv=none; b=LVfaQ3il499ptBHTz2SrI9ED2odV1bqcKKjJjhe7tTle6iGvPI1c/a89iltoz35JQJVgzsEljyDDl94+z7fpqIb/EpTyu9bBoHOYvf25WMQxi96+CygrkN9RITPXkUOipN3MZrncQIte4kvzpXFO8gvdWHPWW2VaTe7ZedN5eRo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722263326; c=relaxed/simple; bh=NehnDBe65QUb/bCNXvqWYiRaGGm51AIYVQytQZgxYgU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=DLw8hTpcNx3qosXabCphwDHYA3itqCZBWNLa5ZNEwU/Fzr1YvJ6xfDFtgSSo6uf9l5/9hoNkM8KzFhdZs9z/szmv5rRq73ieovAW6dPJreFbdAdXpg0LPn/f8ad4cVaI4hvtSy92mXJrP8vd3SJL6Jr8XFWaRifiKF9vutMAtBU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=FOtXgj84; arc=none smtp.client-ip=192.198.163.9 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none 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="FOtXgj84" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1722263324; x=1753799324; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=NehnDBe65QUb/bCNXvqWYiRaGGm51AIYVQytQZgxYgU=; b=FOtXgj84up71elTFBl3vRLf69bRt1Keg0UAy+4sCJCvQcVgtCcPuK2bm tMc4gCBeRhPXvDmavA7DoJPplFlUdd+X32CXEKHtOdIrzvkDbsm9URCm/ 7j0fTuuXG+O1nXIZw5qAZrYD6XNrxK4UUiN7zXahsqO4vlwGVi4UhL+SH dbU23d6SVkPXfAWGjUx6LBx9TMvjwVpTmCB5IMwQXxQjX033n6SEd/suB WrwjV8ghivNSc8exRECvHUobTGpZMf8+bbTJF7SR8kuP6pdsTiPK2XL88 4qInUwOgs9+EBSmLwy0xfBzKspluizfJylglsDmadZu33IDam2Kh+7eJ+ w==; X-CSE-ConnectionGUID: O8ir7Z9KR72SltrmS0KVrA== X-CSE-MsgGUID: OpxW7MNCRX6dyzeF4ubMAA== X-IronPort-AV: E=McAfee;i="6700,10204,11148"; a="30692055" X-IronPort-AV: E=Sophos;i="6.09,246,1716274800"; d="scan'208";a="30692055" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by fmvoesa103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Jul 2024 07:28:43 -0700 X-CSE-ConnectionGUID: aaRxpF21Q2+Qdt21vlrXrw== X-CSE-MsgGUID: TrH4A4xhQ8qG38n6OD5zkQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.09,246,1716274800"; d="scan'208";a="53889098" Received: from hrotuna-mobl2.ger.corp.intel.com (HELO [10.245.246.219]) ([10.245.246.219]) by fmviesa008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Jul 2024 07:28:40 -0700 Message-ID: <095d7119-8221-450a-9616-2df6a0df4c77@linux.intel.com> Date: Mon, 29 Jul 2024 16:25:28 +0200 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] soundwire: stream: fix programming slave ports for non-continous port maps To: Krzysztof Kozlowski , Vinod Koul , Bard Liao , Sanyog Kale , Shreyas NC , alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org References: <20240729140157.326450-1-krzysztof.kozlowski@linaro.org> Content-Language: en-US From: Pierre-Louis Bossart In-Reply-To: <20240729140157.326450-1-krzysztof.kozlowski@linaro.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 7/29/24 16:01, Krzysztof Kozlowski wrote: > Two bitmasks in 'struct sdw_slave_prop' - 'source_ports' and > 'sink_ports' - define which ports to program in > sdw_program_slave_port_params(). The masks are used to get the > appropriate data port properties ('struct sdw_get_slave_dpn_prop') from > an array. > > Bitmasks can be non-continuous or can start from index different than 0, > thus when looking for matching port property for given port, we must > iterate over mask bits, not from 0 up to number of ports. > > This fixes allocation and programming slave ports, when a source or sink > masks start from further index. > > Fixes: f8101c74aa54 ("soundwire: Add Master and Slave port programming") > Cc: > Signed-off-by: Krzysztof Kozlowski This is a valid change to optimize how the port are accessed. But the commit message is not completely clear, the allocation in mipi_disco.c is not modified and I don't think there's anything that would crash. If there are non-contiguous ports, we will still allocate space that will not be initialized/used. /* Allocate memory for set bits in port lists */ nval = hweight32(prop->source_ports); prop->src_dpn_prop = devm_kcalloc(&slave->dev, nval, sizeof(*prop->src_dpn_prop), GFP_KERNEL); if (!prop->src_dpn_prop) return -ENOMEM; /* Read dpn properties for source port(s) */ sdw_slave_read_dpn(slave, prop->src_dpn_prop, nval, prop->source_ports, "source"); IOW, this is a valid change, but it's an optimization, not a fix in the usual sense of 'kernel oops otherwise'. Am I missing something? BTW, the notion of DPn is that n > 0. DP0 is a special case with different properties, BIT(0) cannot be set for either of the sink/source port bitmask. > --- > drivers/soundwire/stream.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c > index 7aa4900dcf31..f275143d7b18 100644 > --- a/drivers/soundwire/stream.c > +++ b/drivers/soundwire/stream.c > @@ -1291,18 +1291,18 @@ struct sdw_dpn_prop *sdw_get_slave_dpn_prop(struct sdw_slave *slave, > unsigned int port_num) > { > struct sdw_dpn_prop *dpn_prop; > - u8 num_ports; > + unsigned long mask; > int i; > > if (direction == SDW_DATA_DIR_TX) { > - num_ports = hweight32(slave->prop.source_ports); > + mask = slave->prop.source_ports; > dpn_prop = slave->prop.src_dpn_prop; > } else { > - num_ports = hweight32(slave->prop.sink_ports); > + mask = slave->prop.sink_ports; > dpn_prop = slave->prop.sink_dpn_prop; > } > > - for (i = 0; i < num_ports; i++) { > + for_each_set_bit(i, &mask, 32) { > if (dpn_prop[i].num == port_num) > return &dpn_prop[i]; > }