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=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 1AE18C43461 for ; Fri, 4 Sep 2020 15:45:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E9054206D4 for ; Fri, 4 Sep 2020 15:45:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726443AbgIDPpZ (ORCPT ); Fri, 4 Sep 2020 11:45:25 -0400 Received: from netrider.rowland.org ([192.131.102.5]:59155 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1726047AbgIDPpS (ORCPT ); Fri, 4 Sep 2020 11:45:18 -0400 Received: (qmail 694637 invoked by uid 1000); 4 Sep 2020 11:45:17 -0400 Date: Fri, 4 Sep 2020 11:45:17 -0400 From: Alan Stern To: Hamish Martin Cc: gregkh@linuxfoundation.org, robh+dt@kernel.org, linux-usb@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] usb: ohci: Add per-port overcurrent quirk Message-ID: <20200904154517.GB694058@rowland.harvard.edu> References: <20200904032247.11345-1-hamish.martin@alliedtelesis.co.nz> <20200904032247.11345-2-hamish.martin@alliedtelesis.co.nz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200904032247.11345-2-hamish.martin@alliedtelesis.co.nz> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 04, 2020 at 03:22:46PM +1200, Hamish Martin wrote: > Some integrated OHCI controller hubs do not expose all ports of the hub > to pins on the SoC. In some cases the unconnected ports generate > spurious overcurrent events. For example the Broadcom 56060/Ranger 2 SoC > contains a nominally 3 port hub but only the first port is wired. > > Default behaviour for ohci-platform driver is to use "ganged" > overcurrent protection mode. This leads to the spurious overcurrent > events affecting all ports in the hub. > > Allow this to be rectified by specifying per-port overcurrent protection > mode via the device tree. > > Signed-off-by: Hamish Martin > --- > drivers/usb/host/ohci-hcd.c | 4 ++++ > drivers/usb/host/ohci-platform.c | 3 +++ > drivers/usb/host/ohci.h | 1 + > 3 files changed, 8 insertions(+) > > diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c > index dd37e77dae00..01e3d75e29d9 100644 > --- a/drivers/usb/host/ohci-hcd.c > +++ b/drivers/usb/host/ohci-hcd.c > @@ -687,6 +687,10 @@ static int ohci_run (struct ohci_hcd *ohci) > val |= RH_A_NPS; > ohci_writel (ohci, val, &ohci->regs->roothub.a); > } > + if (ohci->flags & OHCI_QUIRK_PER_PORT_OC) { > + val |= RH_A_OCPM; > + ohci_writel(ohci, val, &ohci->regs->roothub.a); > + } I don't think this is right, for two reasons. First, isn't per-port overcurrent protection the default? Second, RH_A_OCPM doesn't do anything unless RH_A_NOCP is clear. Alan Stern > ohci_writel (ohci, RH_HS_LPSC, &ohci->regs->roothub.status); > ohci_writel (ohci, (val & RH_A_NPS) ? 0 : RH_B_PPCM, > &ohci->regs->roothub.b); > diff --git a/drivers/usb/host/ohci-platform.c b/drivers/usb/host/ohci-platform.c > index 4a8456f12a73..45e69ce4ef86 100644 > --- a/drivers/usb/host/ohci-platform.c > +++ b/drivers/usb/host/ohci-platform.c > @@ -137,6 +137,9 @@ static int ohci_platform_probe(struct platform_device *dev) > if (of_property_read_bool(dev->dev.of_node, "no-big-frame-no")) > ohci->flags |= OHCI_QUIRK_FRAME_NO; > > + if (of_property_read_bool(dev->dev.of_node, "per-port-overcurrent")) > + ohci->flags |= OHCI_QUIRK_PER_PORT_OC; > + > if (of_property_read_bool(dev->dev.of_node, > "remote-wakeup-connected")) > ohci->hc_control = OHCI_CTRL_RWC; > diff --git a/drivers/usb/host/ohci.h b/drivers/usb/host/ohci.h > index aac6285b37f8..9c2bc816246c 100644 > --- a/drivers/usb/host/ohci.h > +++ b/drivers/usb/host/ohci.h > @@ -422,6 +422,7 @@ struct ohci_hcd { > #define OHCI_QUIRK_AMD_PREFETCH 0x400 /* pre-fetch for ISO transfer */ > #define OHCI_QUIRK_GLOBAL_SUSPEND 0x800 /* must suspend ports */ > #define OHCI_QUIRK_QEMU 0x1000 /* relax timing expectations */ > +#define OHCI_QUIRK_PER_PORT_OC 0x2000 /* per-port overcurrent protection */ > > // there are also chip quirks/bugs in init logic > > -- > 2.28.0 >