From patchwork Sat Aug 29 05:58:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wesley Cheng X-Patchwork-Id: 11744013 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9259D13A4 for ; Sat, 29 Aug 2020 05:59:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C12F20C56 for ; Sat, 29 Aug 2020 05:59:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="fb8rSAOL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726310AbgH2F7B (ORCPT ); Sat, 29 Aug 2020 01:59:01 -0400 Received: from mail29.static.mailgun.info ([104.130.122.29]:11297 "EHLO mail29.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725901AbgH2F7A (ORCPT ); Sat, 29 Aug 2020 01:59:00 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1598680739; h=Content-Transfer-Encoding: MIME-Version: Message-Id: Date: Subject: Cc: To: From: Sender; bh=Qmtfr3sD+DWm7YPaRZ/fa36iliSnR3bJukNjjx9hZQg=; b=fb8rSAOLooAl2e6jHT+O4B/S2vPnbeacBd2/2IQc2eyL/k5Dq5Ubi+Dz0D3wFL0hAaBNxRuc LiYrcFCT8AHOSG67W78L1QWGqsKF+P3KFNhTYmznCJAkqQOUYdfPVcf8e9S1lIab7sSf8PlI s4+f2TczfsxCvpaaJbz20R/9adk= X-Mailgun-Sending-Ip: 104.130.122.29 X-Mailgun-Sid: WyIxZTE2YSIsICJsaW51eC11c2JAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n07.prod.us-west-2.postgun.com with SMTP id 5f49ee9b10b019d039ed7601 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Sat, 29 Aug 2020 05:58:51 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 71ABDC43395; Sat, 29 Aug 2020 05:58:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-caf-mail-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=2.0 tests=ALL_TRUSTED,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.0 Received: from wcheng-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: wcheng) by smtp.codeaurora.org (Postfix) with ESMTPSA id 37267C433C6; Sat, 29 Aug 2020 05:58:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 37267C433C6 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=wcheng@codeaurora.org From: Wesley Cheng To: robh+dt@kernel.org, bjorn.andersson@linaro.org, balbi@kernel.org, gregkh@linuxfoundation.org, agross@kernel.org Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-usb@vger.kernel.org, jackp@codeaurora.org, Wesley Cheng Subject: [RFC v5 0/6] Re-introduce TX FIFO resize for larger EP bursting Date: Fri, 28 Aug 2020 22:58:40 -0700 Message-Id: <20200829055846.19034-1-wcheng@codeaurora.org> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Changes in V5: - Added check_config() logic, which is used to communicate the number of EPs used in a particular configuration. Based on this, the DWC3 gadget driver has the ability to know the maximum number of eps utilized in all configs. This helps reduce unnecessary allocation to unused eps, and will catch fifo allocation issues at bind() time. - Fixed variable declaration to single line per variable, and reverse xmas. - Created a helper for fifo clearing, which is used by ep0.c Changes in V4: - Removed struct dwc3* as an argument for dwc3_gadget_resize_tx_fifos() - Removed WARN_ON(1) in case we run out of fifo space Changes in V3: - Removed "Reviewed-by" tags - Renamed series back to RFC - Modified logic to ensure that fifo_size is reset if we pass the minimum threshold. Tested with binding multiple FDs requesting 6 FIFOs. Changes in V2: - Modified TXFIFO resizing logic to ensure that each EP is reserved a FIFO. - Removed dev_dbg() prints and fixed typos from patches - Added some more description on the dt-bindings commit message Currently, there is no functionality to allow for resizing the TXFIFOs, and relying on the HW default setting for the TXFIFO depth. In most cases, the HW default is probably sufficient, but for USB compositions that contain multiple functions that require EP bursting, the default settings might not be enough. Also to note, the current SW will assign an EP to a function driver w/o checking to see if the TXFIFO size for that particular EP is large enough. (this is a problem if there are multiple HW defined values for the TXFIFO size) It is mentioned in the SNPS databook that a minimum of TX FIFO depth = 3 is required for an EP that supports bursting. Otherwise, there may be frequent occurences of bursts ending. For high bandwidth functions, such as data tethering (protocols that support data aggregation), mass storage, and media transfer protocol (over FFS), the bMaxBurst value can be large, and a bigger TXFIFO depth may prove to be beneficial in terms of USB throughput. (which can be associated to system access latency, etc...) It allows for a more consistent burst of traffic, w/o any interruptions, as data is readily available in the FIFO. With testing done using the mass storage function driver, the results show that with a larger TXFIFO depth, the bandwidth increased significantly. Test Parameters: - Platform: Qualcomm SM8150 - bMaxBurst = 6 - USB req size = 256kB - Num of USB reqs = 16 - USB Speed = Super-Speed - Function Driver: Mass Storage (w/ ramdisk) - Test Application: CrystalDiskMark Results: TXFIFO Depth = 3 max packets Test Case | Data Size | AVG tput (in MB/s) ------------------------------------------- Sequential|1 GB x | Read |9 loops | 193.60 | | 195.86 | | 184.77 | | 193.60 ------------------------------------------- TXFIFO Depth = 6 max packets Test Case | Data Size | AVG tput (in MB/s) ------------------------------------------- Sequential|1 GB x | Read |9 loops | 287.35 | | 304.94 | | 289.64 | | 293.61 ------------------------------------------- Wesley Cheng (6): usb: dwc3: Resize TX FIFOs to meet EP bursting requirements arm64: boot: dts: qcom: sm8150: Enable dynamic TX FIFO resize logic dt-bindings: usb: dwc3: Add entry for tx-fifo-resize usb: gadget: configfs: Check USB configuration before adding usb: gadget: udc: core: Introduce check_config to verify USB configuration usb: dwc3: gadget: Ensure enough TXFIFO space for USB configuration .../devicetree/bindings/usb/dwc3.txt | 2 +- arch/arm64/boot/dts/qcom/sm8150.dtsi | 1 + drivers/usb/dwc3/core.c | 2 + drivers/usb/dwc3/core.h | 7 + drivers/usb/dwc3/ep0.c | 2 + drivers/usb/dwc3/gadget.c | 194 ++++++++++++++++++ drivers/usb/gadget/configfs.c | 22 ++ drivers/usb/gadget/udc/core.c | 9 + include/linux/usb/gadget.h | 2 + 9 files changed, 240 insertions(+), 1 deletion(-)