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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 D9935C7618B for ; Fri, 26 Jul 2019 07:22:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BDAE521873 for ; Fri, 26 Jul 2019 07:22:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726586AbfGZHWk (ORCPT ); Fri, 26 Jul 2019 03:22:40 -0400 Received: from mga04.intel.com ([192.55.52.120]:19721 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725955AbfGZHWj (ORCPT ); Fri, 26 Jul 2019 03:22:39 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Jul 2019 00:22:38 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,309,1559545200"; d="scan'208";a="369451492" Received: from gliakhov-mobl2.ger.corp.intel.com (HELO ubuntu) ([10.249.35.244]) by fmsmga005.fm.intel.com with ESMTP; 26 Jul 2019 00:22:35 -0700 Date: Fri, 26 Jul 2019 09:22:34 +0200 From: Guennadi Liakhovetski To: Pierre-Louis Bossart Cc: alsa-devel@alsa-project.org, tiwai@suse.de, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, vkoul@kernel.org, broonie@kernel.org, srinivas.kandagatla@linaro.org, jank@cadence.com, slawomir.blauciak@intel.com, Sanyog Kale Subject: Re: [alsa-devel] [RFC PATCH 16/40] soundwire: cadence_master: improve startup sequence with link hw_reset Message-ID: <20190726072234.GD16003@ubuntu> References: <20190725234032.21152-1-pierre-louis.bossart@linux.intel.com> <20190725234032.21152-17-pierre-louis.bossart@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190725234032.21152-17-pierre-louis.bossart@linux.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 25, 2019 at 06:40:08PM -0500, Pierre-Louis Bossart wrote: > Enable interrupts first, then engage hardware bus reset with maximum > duration to make sure the Slave(s) correctly detect the reset pattern > and to ensure electrical conflicts can be resolved. > > Without these changes the initialization is randomly corrupted by bus > clashes, parity errors and Slave attachment does not generate any > interrupt, despite the status showing them being attached. > > Signed-off-by: Pierre-Louis Bossart > --- > drivers/soundwire/cadence_master.c | 35 +++++++++++++++++++++++++----- > 1 file changed, 30 insertions(+), 5 deletions(-) > > diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c > index 25d5c7267c15..442f78c00f09 100644 > --- a/drivers/soundwire/cadence_master.c > +++ b/drivers/soundwire/cadence_master.c > @@ -778,6 +778,31 @@ EXPORT_SYMBOL(sdw_cdns_thread); > * init routines > */ > > +static int do_reset(struct sdw_cdns *cdns) > +{ > + int ret; > + > + /* program maximum length reset to be safe */ > + cdns_updatel(cdns, CDNS_MCP_CONTROL, > + CDNS_MCP_CONTROL_RST_DELAY, > + CDNS_MCP_CONTROL_RST_DELAY); > + > + /* use hardware generated reset */ > + cdns_updatel(cdns, CDNS_MCP_CONTROL, > + CDNS_MCP_CONTROL_HW_RST, > + CDNS_MCP_CONTROL_HW_RST); > + > + /* enable bus operations with clock and data */ > + cdns_updatel(cdns, CDNS_MCP_CONFIG, > + CDNS_MCP_CONFIG_OP, > + CDNS_MCP_CONFIG_OP_NORMAL); > + > + /* commit changes */ > + ret = cdns_update_config(cdns); > + > + return ret; + return cdns_update_config(cdns); and remove the "ret" variable. Thanks Guennadi > +} > + > /** > * sdw_cdns_enable_interrupt() - Enable SDW interrupts and update config > * @cdns: Cadence instance > @@ -809,7 +834,7 @@ int sdw_cdns_enable_interrupt(struct sdw_cdns *cdns) > > cdns_writel(cdns, CDNS_MCP_INTMASK, mask); > > - return 0; > + return do_reset(cdns); > } > EXPORT_SYMBOL(sdw_cdns_enable_interrupt); > > @@ -958,6 +983,10 @@ int sdw_cdns_init(struct sdw_cdns *cdns) > cdns_writel(cdns, CDNS_MCP_SSP_CTRL0, CDNS_DEFAULT_SSP_INTERVAL); > cdns_writel(cdns, CDNS_MCP_SSP_CTRL1, CDNS_DEFAULT_SSP_INTERVAL); > > + /* flush command FIFOs */ > + cdns_updatel(cdns, CDNS_MCP_CONTROL, CDNS_MCP_CONTROL_CMD_RST, > + CDNS_MCP_CONTROL_CMD_RST); > + > /* Set cmd accept mode */ > cdns_updatel(cdns, CDNS_MCP_CONTROL, CDNS_MCP_CONTROL_CMD_ACCEPT, > CDNS_MCP_CONTROL_CMD_ACCEPT); > @@ -980,10 +1009,6 @@ int sdw_cdns_init(struct sdw_cdns *cdns) > /* Set cmd mode for Tx and Rx cmds */ > val &= ~CDNS_MCP_CONFIG_CMD; > > - /* Set operation to normal */ > - val &= ~CDNS_MCP_CONFIG_OP; > - val |= CDNS_MCP_CONFIG_OP_NORMAL; > - > cdns_writel(cdns, CDNS_MCP_CONFIG, val); > > /* commit changes */ > -- > 2.20.1 > > _______________________________________________ > Alsa-devel mailing list > Alsa-devel@alsa-project.org > https://mailman.alsa-project.org/mailman/listinfo/alsa-devel