From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3CCD0C43331 for ; Mon, 11 Nov 2019 19:06:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 13D3321655 for ; Mon, 11 Nov 2019 19:06:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573499193; bh=mK+Elh+tbvp7chd+lajcYCegHw9TYGBbrnx4TCYxMNM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Rp+xq9zbzGdtR4MgP3KzH917asGBVtIDhqWnvBvU9gDzxTaS3NmdTBOUoXUIROELT OQLcQHQY1RJR7pZzojMNjhuyUkPFzjf9yY5Fksod37nhPfNLPEObSgEQ92eEZwgd6o SXw8o3zvrqAzjngsaJZFvfhGeQPb0v8U/IQdlL00= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729050AbfKKTGb (ORCPT ); Mon, 11 Nov 2019 14:06:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:57854 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728028AbfKKSiv (ORCPT ); Mon, 11 Nov 2019 13:38:51 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 927592196E; Mon, 11 Nov 2019 18:38:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573497530; bh=mK+Elh+tbvp7chd+lajcYCegHw9TYGBbrnx4TCYxMNM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ascod6o9QoLFL3UkvfiA0vwBLnDjznDZA6tFsKU0Ro/jYIM1k57P67ofYS/RWQowK Af8nNfa4C3oj6sICBPKtR89nOjdDe09RHnKCv07iiJIPGUzz9FUmCzGQ4Tf1CZddVo +0NU0gEjtwYI3sEwwckvdce7L1Thw3APkurkDW0w= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Roger Quadros , Felipe Balbi , Mathieu Poirier Subject: [PATCH 4.14 046/105] usb: dwc3: Allow disabling of metastability workaround Date: Mon, 11 Nov 2019 19:28:16 +0100 Message-Id: <20191111181441.392248271@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191111181421.390326245@linuxfoundation.org> References: <20191111181421.390326245@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Roger Quadros commit 42bf02ec6e420e541af9a47437d0bdf961ca2972 upstream Some platforms (e.g. TI's DRA7 USB2 instance) have more trouble with the metastability workaround as it supports only a High-Speed PHY and the PHY can enter into an Erratic state [1] when the controller is set in SuperSpeed mode as part of the metastability workaround. This causes upto 2 seconds delay in enumeration on DRA7's USB2 instance in gadget mode. If these platforms can be better off without the workaround, provide a device tree property to suggest that so the workaround is avoided. [1] Device mode enumeration trace showing PHY Erratic Error. irq/90-dwc3-969 [000] d... 52.323145: dwc3_event: event (00000901): Erratic Error [U0] irq/90-dwc3-969 [000] d... 52.560646: dwc3_event: event (00000901): Erratic Error [U0] irq/90-dwc3-969 [000] d... 52.798144: dwc3_event: event (00000901): Erratic Error [U0] Signed-off-by: Roger Quadros Signed-off-by: Felipe Balbi Signed-off-by: Mathieu Poirier Signed-off-by: Greg Kroah-Hartman --- Documentation/devicetree/bindings/usb/dwc3.txt | 2 ++ drivers/usb/dwc3/core.c | 3 +++ drivers/usb/dwc3/core.h | 3 +++ drivers/usb/dwc3/gadget.c | 6 ++++-- 4 files changed, 12 insertions(+), 2 deletions(-) --- a/Documentation/devicetree/bindings/usb/dwc3.txt +++ b/Documentation/devicetree/bindings/usb/dwc3.txt @@ -47,6 +47,8 @@ Optional properties: from P0 to P1/P2/P3 without delay. - snps,dis-tx-ipgap-linecheck-quirk: when set, disable u2mac linestate check during HS transmit. + - snps,dis_metastability_quirk: when set, disable metastability workaround. + CAUTION: use only if you are absolutely sure of it. - snps,is-utmi-l1-suspend: true when DWC3 asserts output signal utmi_l1_suspend_n, false when asserts utmi_sleep_n - snps,hird-threshold: HIRD threshold --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -1115,6 +1115,9 @@ static void dwc3_get_properties(struct d device_property_read_u32(dev, "snps,quirk-frame-length-adjustment", &dwc->fladj); + dwc->dis_metastability_quirk = device_property_read_bool(dev, + "snps,dis_metastability_quirk"); + dwc->lpm_nyet_threshold = lpm_nyet_threshold; dwc->tx_de_emphasis = tx_de_emphasis; --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -869,6 +869,7 @@ struct dwc3_scratchpad_array { * 1 - -3.5dB de-emphasis * 2 - No de-emphasis * 3 - Reserved + * @dis_metastability_quirk: set to disable metastability quirk. * @imod_interval: set the interrupt moderation interval in 250ns * increments or 0 to disable. */ @@ -1025,6 +1026,8 @@ struct dwc3 { unsigned tx_de_emphasis_quirk:1; unsigned tx_de_emphasis:2; + unsigned dis_metastability_quirk:1; + u16 imod_interval; }; --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2034,7 +2034,8 @@ static void dwc3_gadget_set_speed(struct * STAR#9000525659: Clock Domain Crossing on DCTL in * USB 2.0 Mode */ - if (dwc->revision < DWC3_REVISION_220A) { + if (dwc->revision < DWC3_REVISION_220A && + !dwc->dis_metastability_quirk) { reg |= DWC3_DCFG_SUPERSPEED; } else { switch (speed) { @@ -3265,7 +3266,8 @@ int dwc3_gadget_init(struct dwc3 *dwc) * is less than super speed because we don't have means, yet, to tell * composite.c that we are USB 2.0 + LPM ECN. */ - if (dwc->revision < DWC3_REVISION_220A) + if (dwc->revision < DWC3_REVISION_220A && + !dwc->dis_metastability_quirk) dev_info(dwc->dev, "changing max_speed on rev %08x\n", dwc->revision);