From patchwork Sat Dec 5 13:55:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 338973 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=-12.2 required=3.0 tests=BAYES_00, DATE_IN_PAST_03_06, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED 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 0D10AC433FE for ; Sat, 5 Dec 2020 18:54:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C147C2310B for ; Sat, 5 Dec 2020 18:54:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726043AbgLESyh (ORCPT ); Sat, 5 Dec 2020 13:54:37 -0500 Received: from ns2.baikalchip.ru ([94.125.187.42]:53406 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1725372AbgLESyh (ORCPT ); Sat, 5 Dec 2020 13:54:37 -0500 From: Serge Semin To: Felipe Balbi , John Youn , Greg Kroah-Hartman , Felipe Balbi , David Cohen , Heikki Krogerus CC: Serge Semin , Serge Semin , Alexey Malahov , Pavel Parkhomenko , , , Felipe Balbi Subject: [PATCH v4 1/3] usb: dwc3: ulpi: Use VStsDone to detect PHY regs access completion Date: Sat, 5 Dec 2020 16:55:19 +0300 Message-ID: <20201205135521.28344-2-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20201205135521.28344-1-Sergey.Semin@baikalelectronics.ru> References: <20201205135521.28344-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org In accordance with [1] the DWC_usb3 core sets the GUSB2PHYACCn.VStsDone bit when the PHY vendor control access is done and clears it when the application initiates a new transaction. The doc doesn't say anything about the GUSB2PHYACCn.VStsBsy flag serving for the same purpose. Moreover we've discovered that the VStsBsy flag can be cleared before the VStsDone bit. So using the former as a signal of the PHY control registers completion might be dangerous. Let's have the VStsDone flag utilized instead then. [1] Synopsys DesignWare Cores SuperSpeed USB 3.0 xHCI Host Controller Databook, 2.70a, December 2013, p.388 Fixes: 88bc9d194ff6 ("usb: dwc3: add ULPI interface support") Signed-off-by: Serge Semin Acked-by: Heikki Krogerus --- Changelog v3: - Add Fixes tag to the commit log. --- drivers/usb/dwc3/core.h | 1 + drivers/usb/dwc3/ulpi.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index 2f95f08ca511..1b241f937d8f 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -285,6 +285,7 @@ /* Global USB2 PHY Vendor Control Register */ #define DWC3_GUSB2PHYACC_NEWREGREQ BIT(25) +#define DWC3_GUSB2PHYACC_DONE BIT(24) #define DWC3_GUSB2PHYACC_BUSY BIT(23) #define DWC3_GUSB2PHYACC_WRITE BIT(22) #define DWC3_GUSB2PHYACC_ADDR(n) (n << 16) diff --git a/drivers/usb/dwc3/ulpi.c b/drivers/usb/dwc3/ulpi.c index aa213c9815f6..3cc4f4970c05 100644 --- a/drivers/usb/dwc3/ulpi.c +++ b/drivers/usb/dwc3/ulpi.c @@ -24,7 +24,7 @@ static int dwc3_ulpi_busyloop(struct dwc3 *dwc) while (count--) { reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0)); - if (!(reg & DWC3_GUSB2PHYACC_BUSY)) + if (reg & DWC3_GUSB2PHYACC_DONE) return 0; cpu_relax(); }