From patchwork Thu May 3 14:43:25 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Daniel_Gl=C3=B6ckner?= X-Patchwork-Id: 10378547 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2688460159 for ; Thu, 3 May 2018 14:43:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1882229198 for ; Thu, 3 May 2018 14:43:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0D4C8291A0; Thu, 3 May 2018 14:43:40 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 67C4D29198 for ; Thu, 3 May 2018 14:43:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751196AbeECOnh (ORCPT ); Thu, 3 May 2018 10:43:37 -0400 Received: from mx1.emlix.com ([46.4.235.150]:52188 "EHLO mx1.emlix.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751050AbeECOnh (ORCPT ); Thu, 3 May 2018 10:43:37 -0400 Received: from mailer.emlix.com (unknown [81.20.119.6]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by mx1.emlix.com (Postfix) with ESMTPS id B847725F71F; Thu, 3 May 2018 16:43:35 +0200 (CEST) Received: by mailer.emlix.com id 1fEFSV-0004Tx-DF; Thu, 03 May 2018 16:43:47 +0200 Received: by devpool05.emlix.com (Postfix, from userid 2059) id 4931D35D13; Thu, 3 May 2018 16:43:35 +0200 (CEST) From: =?UTF-8?q?Daniel=20Gl=C3=B6ckner?= To: linux-usb@vger.kernel.org Cc: Bin Liu , Greg Kroah-Hartman , =?UTF-8?q?Daniel=20Gl=C3=B6ckner?= Subject: [PATCH v2] musb: fix remote wakeup racing with suspend Date: Thu, 3 May 2018 16:43:25 +0200 Message-Id: <20180503144325.20053-1-dg@emlix.com> MIME-Version: 1.0 Organization: emlix gmbh, Goettingen, Germany Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP It has been observed that writing 0xF2 to the power register while it reads as 0xF4 results in the register having the value 0xF0, i.e. clearing RESUME and setting SUSPENDM in one go does not work. It might also violate the USB spec to transition directly from resume to suspend, especially when not taking T_DRSMDN into account. But this is what happens when a remote wakeup occurs between SetPortFeature USB_PORT_FEAT_SUSPEND on the root hub and musb_bus_suspend being called. This commit returns -EBUSY when musb_bus_suspend is called while remote wakeup is signalled and thus avoids to reset the RESUME bit. Ignoring this error when musb_port_suspend is called from musb_hub_control is ok. Signed-off-by: Daniel Glöckner --- drivers/usb/musb/musb_host.c | 5 ++++- drivers/usb/musb/musb_host.h | 7 +++++-- drivers/usb/musb/musb_virthub.c | 25 +++++++++++++++---------- 3 files changed, 24 insertions(+), 13 deletions(-) diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c index 4fa372c..2ae3d50 100644 --- a/drivers/usb/musb/musb_host.c +++ b/drivers/usb/musb/musb_host.c @@ -2522,8 +2522,11 @@ static int musb_bus_suspend(struct usb_hcd *hcd) { struct musb *musb = hcd_to_musb(hcd); u8 devctl; + int ret; - musb_port_suspend(musb, true); + ret = musb_port_suspend(musb, true); + if (ret) + return ret; if (!is_host_active(musb)) return 0; diff --git a/drivers/usb/musb/musb_host.h b/drivers/usb/musb/musb_host.h index 72392bb..2999845 100644 --- a/drivers/usb/musb/musb_host.h +++ b/drivers/usb/musb/musb_host.h @@ -67,7 +67,7 @@ extern void musb_host_rx(struct musb *, u8); extern void musb_root_disconnect(struct musb *musb); extern void musb_host_resume_root_hub(struct musb *musb); extern void musb_host_poke_root_hub(struct musb *musb); -extern void musb_port_suspend(struct musb *musb, bool do_suspend); +extern int musb_port_suspend(struct musb *musb, bool do_suspend); extern void musb_port_reset(struct musb *musb, bool do_reset); extern void musb_host_finish_resume(struct work_struct *work); #else @@ -99,7 +99,10 @@ static inline void musb_root_disconnect(struct musb *musb) {} static inline void musb_host_resume_root_hub(struct musb *musb) {} static inline void musb_host_poll_rh_status(struct musb *musb) {} static inline void musb_host_poke_root_hub(struct musb *musb) {} -static inline void musb_port_suspend(struct musb *musb, bool do_suspend) {} +static inline int musb_port_suspend(struct musb *musb, bool do_suspend) +{ + return 0; +} static inline void musb_port_reset(struct musb *musb, bool do_reset) {} static inline void musb_host_finish_resume(struct work_struct *work) {} #endif diff --git a/drivers/usb/musb/musb_virthub.c b/drivers/usb/musb/musb_virthub.c index 5165d2b..2f8dd98 100644 --- a/drivers/usb/musb/musb_virthub.c +++ b/drivers/usb/musb/musb_virthub.c @@ -48,14 +48,14 @@ void musb_host_finish_resume(struct work_struct *work) spin_unlock_irqrestore(&musb->lock, flags); } -void musb_port_suspend(struct musb *musb, bool do_suspend) +int musb_port_suspend(struct musb *musb, bool do_suspend) { struct usb_otg *otg = musb->xceiv->otg; u8 power; void __iomem *mbase = musb->mregs; if (!is_host_active(musb)) - return; + return 0; /* NOTE: this doesn't necessarily put PHY into low power mode, * turning off its clock; that's a function of PHY integration and @@ -66,16 +66,20 @@ void musb_port_suspend(struct musb *musb, bool do_suspend) if (do_suspend) { int retries = 10000; - power &= ~MUSB_POWER_RESUME; - power |= MUSB_POWER_SUSPENDM; - musb_writeb(mbase, MUSB_POWER, power); + if (power & MUSB_POWER_RESUME) + return -EBUSY; - /* Needed for OPT A tests */ - power = musb_readb(mbase, MUSB_POWER); - while (power & MUSB_POWER_SUSPENDM) { + if (!(power & MUSB_POWER_SUSPENDM)) { + power |= MUSB_POWER_SUSPENDM; + musb_writeb(mbase, MUSB_POWER, power); + + /* Needed for OPT A tests */ power = musb_readb(mbase, MUSB_POWER); - if (retries-- < 1) - break; + while (power & MUSB_POWER_SUSPENDM) { + power = musb_readb(mbase, MUSB_POWER); + if (retries-- < 1) + break; + } } musb_dbg(musb, "Root port suspended, power %02x", power); @@ -111,6 +115,7 @@ void musb_port_suspend(struct musb *musb, bool do_suspend) schedule_delayed_work(&musb->finish_resume_work, msecs_to_jiffies(USB_RESUME_TIMEOUT)); } + return 0; } void musb_port_reset(struct musb *musb, bool do_reset)