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=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 CD730C4363A for ; Tue, 27 Oct 2020 09:15:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 832B822258 for ; Tue, 27 Oct 2020 09:15:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603790135; bh=o5KRhvwObRIIQc6rBh3vrmdNSSuJOyeCIk62E98RJfg=; h=From:To:Cc:Subject:In-Reply-To:References:Date:List-ID:From; b=aTR9MOoEYscx7WP7s2auQCNdXHNFGKNN21TZBLv7rHh4PXB8+dv20OOr5a2Bztwmz ABhUT1/EhbyH0eS0cfuDLWo5kANwEYQlH066RzvN/q7rzU2/IHLgGmVwauKXzMVnOC uU0/yFmVN4lUUDjSwSkj2l7i7GsfB5dw74uwKNuM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439361AbgJ0JPe (ORCPT ); Tue, 27 Oct 2020 05:15:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:60604 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2411637AbgJ0JPe (ORCPT ); Tue, 27 Oct 2020 05:15:34 -0400 Received: from saruman (88-113-213-94.elisa-laajakaista.fi [88.113.213.94]) (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 4A1A722258; Tue, 27 Oct 2020 09:15:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603790132; bh=o5KRhvwObRIIQc6rBh3vrmdNSSuJOyeCIk62E98RJfg=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=z1oLA+RUDnVAlZYMLiieV+BGMBhdaCEYnMv73I489vB5gwnejH1WitUaHxSmQv1dI GXhsGoa37oVDFUlwBfPf8vej2pp+V5DdXCXxFUq+OGNM7w2lx5k8vz6rDvDE5kq1Wj KK478ZVX48QWaYrIoOSU6Zf43fep59D55DCNfAYg= From: Felipe Balbi To: Serge Semin , Greg Kroah-Hartman , Felipe Balbi , Heikki Krogerus , John Youn Cc: Serge Semin , Serge Semin , Alexey Malahov , Pavel Parkhomenko , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] usb: dwc3: ulpi: Use VStsDone to detect PHY regs access completion In-Reply-To: <20201010222351.7323-2-Sergey.Semin@baikalelectronics.ru> References: <20201010222351.7323-1-Sergey.Semin@baikalelectronics.ru> <20201010222351.7323-2-Sergey.Semin@baikalelectronics.ru> Date: Tue, 27 Oct 2020 11:15:24 +0200 Message-ID: <87k0vcc9n7.fsf@kernel.org> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Hi, Serge Semin writes: > 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 > > Signed-off-by: Serge Semin > --- > 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 2f04b3e42bf1..8d5e5bba1bc2 100644 > --- a/drivers/usb/dwc3/core.h > +++ b/drivers/usb/dwc3/core.h > @@ -284,6 +284,7 @@ >=20=20 > /* 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 e6e6176386a4..20f5d9aba317 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) >=20=20 > while (count--) { > reg =3D dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0)); > - if (!(reg & DWC3_GUSB2PHYACC_BUSY)) > + if (reg & DWC3_GUSB2PHYACC_DONE) are you sure this works in all supported versions of the core? John, could you confirm this for us? thanks =2D-=20 balbi --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQJFBAEBCAAvFiEElLzh7wn96CXwjh2IzL64meEamQYFAl+X5SwRHGJhbGJpQGtl cm5lbC5vcmcACgkQzL64meEamQZHxA//fg2g3FbmW01YsryQ46l99nUvp3dxAsRX WasKiojNKREaCkd7bG6XH8oFt+ibwt8Qhdf4yuFuWgNL1+DfH6i91jj2Rg3aBE10 CnslZktzo3cph5My6OLb9QZy0ATXkR59K8tJg7WKkzIFtDHMULYRvUDKF+inwnTC FHnHbe9JLNwhYtgLg/nSZnh7V3Z6CEYD1H9ToAMWQaDh7nb6+W2RqUCaNovSUe4a jB8qrBlKA4hcHV1Xb3XRAHHJ5vFkSR2lSLZlcQLwhz9ACjeE5YEnOsYzZJXk+IB2 jn2NSqc2kW7UyeMoiSO9Vba2tjuEv2u3cgIQoqDzqk/mbCXgcmCtQVRRhnOv/XfD Ar7WdVAOsDpEgpgPHkRA+h5Lj9+7kmy0kvUuj8pDb4lydsOozc0UG1xpfb/SYyYH u28wFrvlnOjWgdCUmnebT1Ar/gP1KT8L/XQWl2ru+Av3FRXqLxjUPDuv1Xo9/Obf TNAsIiqp4thvq39XRIVqMwXcU8zOVWapFFD+Rup0rQq7UgZr+ikRuT6nyqBVrq0U 3n3hiK+Q8z6GnnDjwQ8Mn+1/JoG0KKrY+6fCYNkX6/LaCxKEQpKuhRO20GEDSjy8 Gy/jtG61+yjwCaUd1QY7KAn5Tv+mmCkA5BVXMA/koBFvOGnTFaqSM2xun2LIHOcG Od0Jaw8SHyc= =UFn6 -----END PGP SIGNATURE----- --=-=-=--