From patchwork Thu Feb 8 23:13:20 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wesley Cheng X-Patchwork-Id: 13550702 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) (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 16A0B51005; Thu, 8 Feb 2024 23:14:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.180.131 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707434086; cv=none; b=O7KQn7IptwxbWD5/QYXHbZE60pOEZv4BRDyH/K5UAqtM7w2+S4s26JIcEMkQZYSUGI1idxYZho5bXRhvxAiuyIBes9ZA1RFWKLJSxmOdkRFIdrT9Vxwx0hKZb8sLBcxQRpPDvLV/q492hSTwSeYMD4A0q/7IZ2yaoGbo+o9HznQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707434086; c=relaxed/simple; bh=9xhUO2oBg3VGby3vuFrh+xyofs8aRXlLZClt/1/wQLY=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=tOBF34oOWskuAdSDwjXp4/Z80THS491UP0J4iLrIYMhRGU6gseKdnVOgjBipbh53Pf2k8tsP8OMf8AtzDkkKnY23Jr5UqC5skgCCGObhI49YEMu/WnaFnA+cooy56u4/XU96K4hga6FXNq1PJ/TrCw6XMphm/2s7CLx0RTUXNI4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com; spf=pass smtp.mailfrom=quicinc.com; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b=AEBApGw/; arc=none smtp.client-ip=205.220.180.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=quicinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b="AEBApGw/" Received: from pps.filterd (m0279873.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.24/8.17.1.24) with ESMTP id 418Mk55W029816; Thu, 8 Feb 2024 23:14:19 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h= from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-type; s=qcppdkim1; bh=e3ZP4UGfMJHN9tb9hE1a TUT7cHSD1ZLTE7FnRsZFK6Q=; b=AEBApGw/IkkSrovJhMhdHqhx/5YmH5UwFutq NcqlEU8nn2qvyDNBKEofFhdBlQFno0LUc3SMcAns3QWmDMZeBZcyJtQtR01OQre4 jRMfL+NSIERXEvWPPMQCyJOs10zjLDY9wWWpz+7FAp/8ckbrobkXH4J5UIu8vEEa Anw+NvwdVqgnlSmaL4RJhBfkOL/UHb/tDpyTF8SRTL3W6gUiZVTQmoKng3nCZ05F EjmrpvRgq4Wl56nR33BNYAUw0rkAoVev/zTkwAbCgyFQrhDrPQLzf5izTKubjoFb pIagp1OFB3Dx77tW59XUfIJLfP206MhS1rP5mVVzRT2LuOXVuw== Received: from nalasppmta05.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3w4m3ak1p9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 08 Feb 2024 23:14:19 +0000 (GMT) Received: from nalasex01b.na.qualcomm.com (nalasex01b.na.qualcomm.com [10.47.209.197]) by NALASPPMTA05.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 418NEIGl012196 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 8 Feb 2024 23:14:18 GMT Received: from hu-wcheng-lv.qualcomm.com (10.49.16.6) by nalasex01b.na.qualcomm.com (10.47.209.197) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.40; Thu, 8 Feb 2024 15:14:17 -0800 From: Wesley Cheng To: , , , , , , , , , , , , , , CC: , , , , , , , Mathias Nyman , Wesley Cheng Subject: [PATCH v14 07/53] xhci: update event ring dequeue pointer position to controller correctly Date: Thu, 8 Feb 2024 15:13:20 -0800 Message-ID: <20240208231406.27397-8-quic_wcheng@quicinc.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20240208231406.27397-1-quic_wcheng@quicinc.com> References: <20240208231406.27397-1-quic_wcheng@quicinc.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: nalasex01c.na.qualcomm.com (10.47.97.35) To nalasex01b.na.qualcomm.com (10.47.209.197) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-ORIG-GUID: sP22P7Fda8SrKVI3FRS9q_RMAUOS53sY X-Proofpoint-GUID: sP22P7Fda8SrKVI3FRS9q_RMAUOS53sY X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.1011,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2024-02-08_11,2024-02-08_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 suspectscore=0 bulkscore=0 lowpriorityscore=0 impostorscore=0 phishscore=0 mlxlogscore=999 adultscore=0 priorityscore=1501 malwarescore=0 spamscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2401310000 definitions=main-2402080131 From: Mathias Nyman The event ring dequeue pointer field (ERDP) in xHC hardware is used to inform controller how far the driver has processed events on the event ring. In the case all events are handled and event ring is empty then the address of the TRB after the last processed one should be written. This TRB is both the enqueue and dequeue pointer. But in case we are writing the ERDP in the middle of processing several events then ERDP field should be written with the "up to and including" address of the last handled event TRB. Currenly each ERDP write by driver is done as if all events are handled and ring is empty. Fix this by adjusting the order when software dequeue "inc_deq()" is called and hardware dequeue "xhci_update_erst_dequeue()" is updated. Details in xhci 1.2 specification section 4.9.4: "System software shall write the Event Ring Dequeue Pointer (ERDP) register to inform the xHC that it has completed the processing of Event TRBs up to and including the Event TRB referenced by the ERDP. The detection of a Cycle bit mismatch in an Event TRB processed by software indicates the location of the xHC Event Ring Enqueue Pointer and that the Event Ring is empty. Software shall write the ERDP with the address of this TRB to indicate that it has processed all Events in the ring" This change depends on fixes made to relocate inc_deq() calls captured in the below commits: commit 3321f84bfae0 ("xhci: simplify event ring dequeue tracking for transfer events") commit d1830364e963 ("xhci: Simplify event ring dequeue pointer update for port change events") Fixes: dc0ffbea5729 ("usb: host: xhci: update event ring dequeue pointer on purpose") Signed-off-by: Mathias Nyman Signed-off-by: Wesley Cheng --- drivers/usb/host/xhci-ring.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index a9d2e876d62b..0289d77839cf 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2966,9 +2966,6 @@ static int xhci_handle_event(struct xhci_hcd *xhci, struct xhci_interrupter *ir) return 0; } - /* Update SW event ring dequeue pointer */ - inc_deq(xhci, ir->event_ring); - /* Are there more items on the event ring? Caller will call us again to * check. */ @@ -3091,15 +3088,21 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd) * that clears the EHB. */ while (xhci_handle_event(xhci, ir) > 0) { - if (event_loop++ < TRBS_PER_SEGMENT / 2) - continue; - xhci_update_erst_dequeue(xhci, ir, false); + /* + * If half a segment of events have been handled in one go then + * update ERDP, and force isoc trbs to interrupt more often + */ + if (event_loop++ > TRBS_PER_SEGMENT / 2) { + xhci_update_erst_dequeue(xhci, ir, false); + + if (ir->isoc_bei_interval > AVOID_BEI_INTERVAL_MIN) + ir->isoc_bei_interval = ir->isoc_bei_interval / 2; - /* ring is half-full, force isoc trbs to interrupt more often */ - if (ir->isoc_bei_interval > AVOID_BEI_INTERVAL_MIN) - ir->isoc_bei_interval = ir->isoc_bei_interval / 2; + event_loop = 0; + } - event_loop = 0; + /* Update SW event ring dequeue pointer */ + inc_deq(xhci, ir->event_ring); } xhci_update_erst_dequeue(xhci, ir, true);