From patchwork Wed Sep 14 12:09:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Fitzgerald X-Patchwork-Id: 606465 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 C8B12ECAAD3 for ; Wed, 14 Sep 2022 12:11:02 +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 9F916185A; Wed, 14 Sep 2022 14:10:09 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 9F916185A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1663157459; bh=sdTncHjHA0gaGHwrGAlljZxHPR6Y9wlY9e9zl+b4aGo=; h=From:To:Subject:Date:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=BNRwDCLSzusXLqkechMKHI66sH+k7laHMIZdDMyReKX/oh6l8k9BQu4rrX/9nJRWj wxMoF/ugwNjRJnuDePakW9dPkHc+VlhSZqe9o8chp2naABRu6LNwqZHCQWFcmc/vXs Vr9L6YhWCQ3C6AdmpHVcWmBfq53szmgF6xyBRUdk= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 02A98F800C0; Wed, 14 Sep 2022 14:10:09 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 8A357F80507; Wed, 14 Sep 2022 14:10:06 +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 E0B7EF8008E for ; Wed, 14 Sep 2022 14:09:59 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz E0B7EF8008E Authentication-Results: alsa1.perex.cz; dkim=pass (2048-bit key) header.d=cirrus.com header.i=@cirrus.com header.b="FxHPAHNi" 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 28EBt7vM003707; Wed, 14 Sep 2022 07:09:58 -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=jSHVQM4f5c6nFOJUjjIDepmDXBFYw20rCfoBuGjpZxs=; b=FxHPAHNiev5LqKQxwq0fhh0knh9A3L+fH54NJHCdxxvwRcq7dNdE4bZ4pCexu3cY+Jet ULK78uyyKPdBowMSnAtXJocNnxAm4NVZ1eFr6GEOw3allWpqaOlXPce85ODQreR36lDx DGcJH6uSTRCoHlYtJv06oXPJMYghdIh0ymYtaDCo57/1A65ad8RsHGIFoS5aDnPJAFrQ PPOe5c/vdiOieIrITyTI2dy76Kl9om1CGmRQK4J9JageyUYul70fwVxM+vee6o8rxyr5 6idGa1w6Z73O+g2FFG5blxvgJigbHEXU868KUh7KCdVe8uTdwz18Jer4rMAG8A2xZPkg OA== Received: from ediex01.ad.cirrus.com ([84.19.233.68]) by mx0b-001ae601.pphosted.com (PPS) with ESMTPS id 3jjxyr0xed-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 14 Sep 2022 07:09:58 -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; Wed, 14 Sep 2022 07:09:56 -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; Wed, 14 Sep 2022 07:09:56 -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 4796B11DA; Wed, 14 Sep 2022 12:09:56 +0000 (UTC) From: Richard Fitzgerald To: , , , Subject: [PATCH v3 3/5] soundwire: bus: Don't re-enumerate before status is UNATTACHED Date: Wed, 14 Sep 2022 13:09:47 +0100 Message-ID: <20220914120949.747951-4-rf@opensource.cirrus.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220914120949.747951-1-rf@opensource.cirrus.com> References: <20220914120949.747951-1-rf@opensource.cirrus.com> MIME-Version: 1.0 X-Proofpoint-ORIG-GUID: xIMthwqaKpNG13HZSLZ4sCZHWrLoNil9 X-Proofpoint-GUID: xIMthwqaKpNG13HZSLZ4sCZHWrLoNil9 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 Reviewed-by: Pierre-Louis Bossart --- drivers/soundwire/bus.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 1cc858b4107d..6e569a875a9b 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -773,6 +773,16 @@ static int sdw_program_device_num(struct sdw_bus *bus) if (sdw_compare_devid(slave, id) == 0) { found = true; + /* + * To prevent skipping state-machine stages don't + * program a device until we've seen it UNATTACH. + * Must return here because no other device on #0 + * can be detected until this one has been + * assigned a device ID. + */ + if (slave->status != SDW_SLAVE_UNATTACHED) + return 0; + /* * Assign a new dev_num to this Slave and * not mark it present. It will be marked