From patchwork Mon Aug 29 09:44:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Fitzgerald X-Patchwork-Id: 600869 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EB8A1ECAAD4 for ; Mon, 29 Aug 2022 09:46:28 +0000 (UTC) Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id DEB9FAE9; Mon, 29 Aug 2022 11:45:36 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz DEB9FAE9 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1661766387; bh=Fk1vRi+CHZt2dI59AiW5JdBa2ubtLD2dwpb7C1t7zHE=; h=From:To:Subject:Date:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=GXebWSOvdQ38GRo29//G6c29SW/rh87A5uxhUX0tAOhAzXCfLQWy4rB/gbo9g2IQF PZc6F6UUK5AGsu9ZVmji0QEMqCgraz70yOzMoZeKIqfsoxH7NxsKR/5Yb7LvtiGNZK vLESE0An/LfijsbvFS0zyaxCgPkC8PjuWaNYp/4E= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 3FEFDF80217; Mon, 29 Aug 2022 11:45:11 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 71405F803DC; Mon, 29 Aug 2022 11:45:10 +0200 (CEST) Received: from mx0b-001ae601.pphosted.com (mx0b-001ae601.pphosted.com [67.231.152.168]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 1A3A1F80115 for ; Mon, 29 Aug 2022 11:45:02 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 1A3A1F80115 Authentication-Results: alsa1.perex.cz; dkim=pass (2048-bit key) header.d=cirrus.com header.i=@cirrus.com header.b="Dk1dd8hr" Received: from pps.filterd (m0077474.ppops.net [127.0.0.1]) by mx0b-001ae601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 27T5g85l004126; Mon, 29 Aug 2022 04:45:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cirrus.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=PODMain02222019; bh=MRh3A4ON0/ZCyZM67h+hhoZTvgjWZJM7VSH6yQSQ1YQ=; b=Dk1dd8hrOFdMLDmFmZ+exP6t6QGPuRS42OmQLp8noSC1eN8YGVO8Ha/oaknVwBILvd2f VH1nLhLEcLkOOLYVyGmi+kyK3mZCADtMe+gd1ZgV4vlQz4STxh8tCZ4w6+WJ2XNP69Q5 ELGkMS8lK2OV3+FHkW6R9C+RPIVRaqb+aQ2Gv7tKMctk6t9FodbnJwopbI5cBecAMMeK JYVfEICmOKfEw6tVTLWCSVUzArbiqDpsDW0KqdUCiw8xeLrZ1d884bo2/cQDfkrsCXOX MNI0yapatetmRp3rQ8xYUMB7a+nikYKBxPz76gL7QXZPHLbr0DxW3BFudfj+4o66Dhy6 ww== Received: from ediex01.ad.cirrus.com ([84.19.233.68]) by mx0b-001ae601.pphosted.com (PPS) with ESMTPS id 3j7fpp9v2g-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 29 Aug 2022 04:45:00 -0500 Received: from ediex01.ad.cirrus.com (198.61.84.80) by ediex01.ad.cirrus.com (198.61.84.80) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.12; Mon, 29 Aug 2022 04:44:58 -0500 Received: from ediswmail.ad.cirrus.com (198.61.86.93) by ediex01.ad.cirrus.com (198.61.84.80) with Microsoft SMTP Server id 15.2.1118.12 via Frontend Transport; Mon, 29 Aug 2022 04:44:58 -0500 Received: from edi-sw-dsktp-006.ad.cirrus.com (edi-sw-dsktp-006.ad.cirrus.com [198.90.251.95]) by ediswmail.ad.cirrus.com (Postfix) with ESMTP id DE62D459; Mon, 29 Aug 2022 09:44:58 +0000 (UTC) From: Richard Fitzgerald To: , , , Subject: [PATCH 1/1] soundwire: bus: Don't re-enumerate before status is UNATTACHED Date: Mon, 29 Aug 2022 10:44:58 +0100 Message-ID: <20220829094458.1169504-2-rf@opensource.cirrus.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220829094458.1169504-1-rf@opensource.cirrus.com> References: <20220829094458.1169504-1-rf@opensource.cirrus.com> MIME-Version: 1.0 X-Proofpoint-GUID: gDoi_kzPveKJ2u67J1CTVKk8KYUoFZ4d X-Proofpoint-ORIG-GUID: gDoi_kzPveKJ2u67J1CTVKk8KYUoFZ4d X-Proofpoint-Spam-Reason: safe Cc: patches@opensource.cirrus.com, alsa-devel@alsa-project.org, Richard Fitzgerald , linux-kernel@vger.kernel.org X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" Don't re-enumerate a peripheral on #0 until we have seen and handled an UNATTACHED notification for that peripheral. Without this, it is possible for the UNATTACHED status to be missed and so the slave->status remains at ATTACHED. If slave->status never changes to UNATTACHED the child driver will never be notified of the UNATTACH, and the code in sdw_handle_slave_status() will skip the second part of enumeration because the slave->status has not changed. This scenario can happen because PINGs are handled in a workqueue function which is working from a snapshot of an old PING, and there is no guarantee when this function will run. A peripheral could report attached in the PING being handled by sdw_handle_slave_status(), but has since reverted to device #0 and is then found in the loop in sdw_program_device_num(). Previously the code would not have updated slave->status to UNATTACHED because it had not yet handled a PING where that peripheral had UNATTACHED. This situation happens fairly frequently with multiple peripherals on a bus that are intentionally reset (for example after downloading firmware). Signed-off-by: Richard Fitzgerald --- drivers/soundwire/bus.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index cb77da84a4f9..a3d3d66b3410 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -766,6 +766,13 @@ static int sdw_program_device_num(struct sdw_bus *bus) if (sdw_compare_devid(slave, id) == 0) { found = true; + /* + * Don't re-enumerate a device until we've seen + * it UNATTACH. + */ + if (slave->status != SDW_SLAVE_UNATTACHED) + break; + /* * Assign a new dev_num to this Slave and * not mark it present. It will be marked