From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83C27C4361B for ; Sat, 5 Dec 2020 18:38:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 590D12312B for ; Sat, 5 Dec 2020 18:38:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726301AbgLESho (ORCPT ); Sat, 5 Dec 2020 13:37:44 -0500 Received: from mga01.intel.com ([192.55.52.88]:30676 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726061AbgLEShl (ORCPT ); Sat, 5 Dec 2020 13:37:41 -0500 IronPort-SDR: H8BQQ1+mhM7d55BXRhAhDh3aCGd4opVJYhSuKis3CgmU7lMRCMb994vEo6EDJXGCKGgnq0vAy2 klqdG7tD4mHw== X-IronPort-AV: E=McAfee;i="6000,8403,9825"; a="191774459" X-IronPort-AV: E=Sophos;i="5.78,395,1599548400"; d="scan'208";a="191774459" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Dec 2020 06:59:56 -0800 IronPort-SDR: RYoMDGFFTE6jxc6pGLX2RQcbEpvcChRMU2DhisSbvvl+p0aMw7PNIZxacFcm8U16RJ6X5brham vKsXrkEViP1Q== X-IronPort-AV: E=Sophos;i="5.78,395,1599548400"; d="scan'208";a="436104270" Received: from schamb2-mobl2.amr.corp.intel.com (HELO [10.212.89.161]) ([10.212.89.161]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Dec 2020 06:59:55 -0800 Subject: Re: [PATCH 1/7] soundwire: bus: use sdw_update_no_pm when initializing a device To: Vinod Koul , Bard Liao Cc: alsa-devel@alsa-project.org, tiwai@suse.de, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, ranjani.sridharan@linux.intel.com, hui.wang@canonical.com, broonie@kernel.org, srinivas.kandagatla@linaro.org, jank@cadence.com, sanyog.r.kale@intel.com, rander.wang@linux.intel.com, bard.liao@intel.com References: <20201202204645.23891-1-yung-chuan.liao@linux.intel.com> <20201202204645.23891-2-yung-chuan.liao@linux.intel.com> <20201205074508.GQ8403@vkoul-mobl> From: Pierre-Louis Bossart Message-ID: <1db93c2e-3c87-bc5e-ddeb-56424870b897@linux.intel.com> Date: Sat, 5 Dec 2020 08:59:01 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201205074508.GQ8403@vkoul-mobl> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thanks for the review Vinod. On 12/5/20 1:45 AM, Vinod Koul wrote: > On 03-12-20, 04:46, Bard Liao wrote: >> From: Pierre-Louis Bossart >> >> When a Slave device is resumed, it may resume the bus and restart the >> enumeration. During that process, we absolutely don't want to call >> regular read/write routines which will wait for the resume to >> complete, otherwise a deadlock occurs. >> >> Fixes: 60ee9be25571 ('soundwire: bus: add PM/no-PM versions of read/write functions') > > Change looks okay, but not sure why this is a fix for adding no pm > version? when we added the no_pm version, we missed the two cases below where sdw_update() was used and that creates a deadlock. To me that's a conceptual bug, we didn't fully use the no_pm versions, hence the Fixes tag. It's ok to remove the tag if you don't think it's useful/relevant, what matters is that we agree on the content. >> Signed-off-by: Pierre-Louis Bossart >> Reviewed-by: Rander Wang >> Signed-off-by: Bard Liao >> --- >> drivers/soundwire/bus.c | 16 ++++++++++++++-- >> 1 file changed, 14 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c >> index d1e8c3a54976..60c42508c6c6 100644 >> --- a/drivers/soundwire/bus.c >> +++ b/drivers/soundwire/bus.c >> @@ -489,6 +489,18 @@ sdw_read_no_pm(struct sdw_slave *slave, u32 addr) >> return buf; >> } >> >> +static int sdw_update_no_pm(struct sdw_slave *slave, u32 addr, u8 mask, u8 val) >> +{ >> + int tmp; >> + >> + tmp = sdw_read_no_pm(slave, addr); >> + if (tmp < 0) >> + return tmp; >> + >> + tmp = (tmp & ~mask) | val; >> + return sdw_write_no_pm(slave, addr, tmp); >> +} >> + >> /** >> * sdw_nread() - Read "n" contiguous SDW Slave registers >> * @slave: SDW Slave >> @@ -1256,7 +1268,7 @@ static int sdw_initialize_slave(struct sdw_slave *slave) >> val = slave->prop.scp_int1_mask; >> >> /* Enable SCP interrupts */ >> - ret = sdw_update(slave, SDW_SCP_INTMASK1, val, val); >> + ret = sdw_update_no_pm(slave, SDW_SCP_INTMASK1, val, val); >> if (ret < 0) { >> dev_err(slave->bus->dev, >> "SDW_SCP_INTMASK1 write failed:%d\n", ret); >> @@ -1271,7 +1283,7 @@ static int sdw_initialize_slave(struct sdw_slave *slave) >> val = prop->dp0_prop->imp_def_interrupts; >> val |= SDW_DP0_INT_PORT_READY | SDW_DP0_INT_BRA_FAILURE; >> >> - ret = sdw_update(slave, SDW_DP0_INTMASK, val, val); >> + ret = sdw_update_no_pm(slave, SDW_DP0_INTMASK, val, val); >> if (ret < 0) >> dev_err(slave->bus->dev, >> "SDW_DP0_INTMASK read failed:%d\n", ret); >> -- >> 2.17.1 >