From patchwork Mon May 23 21:39:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wesley Cheng X-Patchwork-Id: 576230 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 870B9C433F5 for ; Mon, 23 May 2022 21:40:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231361AbiEWVkq (ORCPT ); Mon, 23 May 2022 17:40:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49214 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230154AbiEWVkp (ORCPT ); Mon, 23 May 2022 17:40:45 -0400 Received: from alexa-out.qualcomm.com (alexa-out.qualcomm.com [129.46.98.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 506A461605; Mon, 23 May 2022 14:40:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1653342042; x=1684878042; h=from:to:cc:subject:date:message-id:mime-version; bh=O0X78NDShcEC3E1BhKeb5ph3+0rFHeFiCWCbSngXDXI=; b=bEMAE9hgYXOqfeu5ON0ToEb06dZPuKP/Vahh8nbCzgt2lLNCFSK93+Ps t8TZ29a5ORJphuvAZl5MaDrPUSv74pS4J2eDRopiBKpPUbkxDafKmco+p Kz3thze+F4iFkEwsOu6O+CTIO5aX2UOgGn8sdeS5J4VFjDji9GhrKMEyt U=; Received: from ironmsg08-lv.qualcomm.com ([10.47.202.152]) by alexa-out.qualcomm.com with ESMTP; 23 May 2022 14:40:41 -0700 X-QCInternal: smtphost Received: from nasanex01c.na.qualcomm.com ([10.47.97.222]) by ironmsg08-lv.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 May 2022 14:40:41 -0700 Received: from nalasex01b.na.qualcomm.com (10.47.209.197) by nasanex01c.na.qualcomm.com (10.47.97.222) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.22; Mon, 23 May 2022 14:40:01 -0700 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 15.2.986.22; Mon, 23 May 2022 14:40:00 -0700 From: Wesley Cheng To: , CC: , , , , Wesley Cheng Subject: [PATCH] usb: dwc3: gadget: Fix IN endpoint max packet size allocation Date: Mon, 23 May 2022 14:39:48 -0700 Message-ID: <20220523213948.22142-1-quic_wcheng@quicinc.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.49.16.6] X-ClientProxiedBy: nalasex01a.na.qualcomm.com (10.47.209.196) To nalasex01b.na.qualcomm.com (10.47.209.197) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org The current logic to assign the max packet limit for IN endpoints attempts to take the default HW value and apply the optimal endpoint settings based on it. However, if the default value reports a TxFIFO size large enough for only one max packet, it will divide the value and assign a smaller ep max packet limit. For example, if the default TxFIFO size fits 1024B, current logic will assign 1024/3 = 341B to ep max packet size. If function drivers attempt to request for an endpoint with a wMaxPacketSize of 1024B (SS BULK max packet size) then it will fail, as the gadget is unable to find an endpoint which can fit the requested size. Functionally, if the TxFIFO has enough space to fit one max packet, it will be sufficient, at least when initializing the endpoints. Fixes: d94ea5319813 ("usb: dwc3: gadget: Properly set maxpacket limit") Signed-off-by: Wesley Cheng --- drivers/usb/dwc3/gadget.c | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 4f54f0ef21df..c201df4743b9 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2974,6 +2974,7 @@ static int dwc3_gadget_init_in_endpoint(struct dwc3_ep *dep) struct dwc3 *dwc = dep->dwc; u32 mdwidth; int size; + int maxpacket; mdwidth = dwc3_mdwidth(dwc); @@ -2986,21 +2987,24 @@ static int dwc3_gadget_init_in_endpoint(struct dwc3_ep *dep) else size = DWC31_GTXFIFOSIZ_TXFDEP(size); - /* FIFO Depth is in MDWDITH bytes. Multiply */ - size *= mdwidth; - /* - * To meet performance requirement, a minimum TxFIFO size of 3x - * MaxPacketSize is recommended for endpoints that support burst and a - * minimum TxFIFO size of 2x MaxPacketSize for endpoints that don't - * support burst. Use those numbers and we can calculate the max packet - * limit as below. + * maxpacket size is determined as part of the following, after assuming + * a mult value of one maxpacket: + * DWC3 revision 280A and prior: + * fifo_size = mult * (max_packet / mdwidth) + 1; + * maxpacket = mdwidth * (fifo_size - 1); + * + * DWC3 revision 290A and onwards: + * fifo_size = mult * ((max_packet + mdwidth)/mdwidth + 1) + 1 + * maxpacket = mdwidth * ((fifo_size - 1) - 1) - mdwidth; */ - if (dwc->maximum_speed >= USB_SPEED_SUPER) - size /= 3; + if (DWC3_VER_IS_PRIOR(DWC3, 290A)) + maxpacket = mdwidth * (size - 1); else - size /= 2; + maxpacket = mdwidth * ((size - 1) - 1) - mdwidth; + /* Functionally, space for one max packet is sufficient */ + size = min_t(int, maxpacket, 1024); usb_ep_set_maxpacket_limit(&dep->endpoint, size); dep->endpoint.max_streams = 16;