From patchwork Wed Dec 5 12:22:38 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mathias Nyman X-Patchwork-Id: 10713969 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 813F618B8 for ; Wed, 5 Dec 2018 12:18:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 714A62C2B3 for ; Wed, 5 Dec 2018 12:18:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6544B2C2D1; Wed, 5 Dec 2018 12:18:58 +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 D3F002C2C0 for ; Wed, 5 Dec 2018 12:18:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727826AbeLEMSz (ORCPT ); Wed, 5 Dec 2018 07:18:55 -0500 Received: from mga18.intel.com ([134.134.136.126]:29821 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727242AbeLEMSy (ORCPT ); Wed, 5 Dec 2018 07:18:54 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Dec 2018 04:18:53 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,317,1539673200"; d="scan'208";a="116160783" Received: from mattu-haswell.fi.intel.com ([10.237.72.164]) by orsmga001.jf.intel.com with ESMTP; 05 Dec 2018 04:18:50 -0800 From: Mathias Nyman To: Cc: , Sandeep Singh , Shyam Sundar S K , Sandeep Singh , Nehal Shah , stable@vger.kernel.org, Mathias Nyman Subject: [PATCH 1/2] xhci: workaround CSS timeout on AMD SNPS 3.0 xHC Date: Wed, 5 Dec 2018 14:22:38 +0200 Message-Id: <1544012559-20871-2-git-send-email-mathias.nyman@linux.intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1544012559-20871-1-git-send-email-mathias.nyman@linux.intel.com> References: <1544012559-20871-1-git-send-email-mathias.nyman@linux.intel.com> 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 From: Sandeep Singh Occasionally AMD SNPS 3.0 xHC does not respond to CSS when set, also it does not flag anything on SRE and HCE to point the internal xHC errors on USBSTS register. This stalls the entire system wide suspend and there is no point in stalling just because of xHC CSS is not responding. To work around this problem, if the xHC does not flag anything on SRE and HCE, we can skip the CSS timeout and allow the system to continue the suspend. Once the system resume happens we can internally reset the controller using XHCI_RESET_ON_RESUME quirk Signed-off-by: Shyam Sundar S K Signed-off-by: Sandeep Singh cc: Nehal Shah Cc: Tested-by: Kai-Heng Feng Signed-off-by: Mathias Nyman --- drivers/usb/host/xhci-pci.c | 4 ++++ drivers/usb/host/xhci.c | 26 ++++++++++++++++++++++---- drivers/usb/host/xhci.h | 3 +++ 3 files changed, 29 insertions(+), 4 deletions(-) diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c index a951526..a9ec705 100644 --- a/drivers/usb/host/xhci-pci.c +++ b/drivers/usb/host/xhci-pci.c @@ -139,6 +139,10 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci) pdev->device == 0x43bb)) xhci->quirks |= XHCI_SUSPEND_DELAY; + if (pdev->vendor == PCI_VENDOR_ID_AMD && + (pdev->device == 0x15e0 || pdev->device == 0x15e1)) + xhci->quirks |= XHCI_SNPS_BROKEN_SUSPEND; + if (pdev->vendor == PCI_VENDOR_ID_AMD) xhci->quirks |= XHCI_TRUST_TX_LENGTH; diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index c928dbb..c20b85e 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -968,6 +968,7 @@ int xhci_suspend(struct xhci_hcd *xhci, bool do_wakeup) unsigned int delay = XHCI_MAX_HALT_USEC; struct usb_hcd *hcd = xhci_to_hcd(xhci); u32 command; + u32 res; if (!hcd->state) return 0; @@ -1021,11 +1022,28 @@ int xhci_suspend(struct xhci_hcd *xhci, bool do_wakeup) command = readl(&xhci->op_regs->command); command |= CMD_CSS; writel(command, &xhci->op_regs->command); + xhci->broken_suspend = 0; if (xhci_handshake(&xhci->op_regs->status, STS_SAVE, 0, 10 * 1000)) { - xhci_warn(xhci, "WARN: xHC save state timeout\n"); - spin_unlock_irq(&xhci->lock); - return -ETIMEDOUT; + /* + * AMD SNPS xHC 3.0 occasionally does not clear the + * SSS bit of USBSTS and when driver tries to poll + * to see if the xHC clears BIT(8) which never happens + * and driver assumes that controller is not responding + * and times out. To workaround this, its good to check + * if SRE and HCE bits are not set (as per xhci + * Section 5.4.2) and bypass the timeout. + */ + res = readl(&xhci->op_regs->status); + if ((xhci->quirks & XHCI_SNPS_BROKEN_SUSPEND) && + (((res & STS_SRE) == 0) && + ((res & STS_HCE) == 0))) { + xhci->broken_suspend = 1; + } else { + xhci_warn(xhci, "WARN: xHC save state timeout\n"); + spin_unlock_irq(&xhci->lock); + return -ETIMEDOUT; + } } spin_unlock_irq(&xhci->lock); @@ -1078,7 +1096,7 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated) set_bit(HCD_FLAG_HW_ACCESSIBLE, &xhci->shared_hcd->flags); spin_lock_irq(&xhci->lock); - if (xhci->quirks & XHCI_RESET_ON_RESUME) + if ((xhci->quirks & XHCI_RESET_ON_RESUME) || xhci->broken_suspend) hibernated = true; if (!hibernated) { diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 260b259..c3515ba 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1850,6 +1850,7 @@ struct xhci_hcd { #define XHCI_ZERO_64B_REGS BIT_ULL(32) #define XHCI_DEFAULT_PM_RUNTIME_ALLOW BIT_ULL(33) #define XHCI_RESET_PLL_ON_DISCONNECT BIT_ULL(34) +#define XHCI_SNPS_BROKEN_SUSPEND BIT_ULL(35) unsigned int num_active_eps; unsigned int limit_active_eps; @@ -1879,6 +1880,8 @@ struct xhci_hcd { void *dbc; /* platform-specific data -- must come last */ unsigned long priv[0] __aligned(sizeof(s64)); + /* Broken Suspend flag for SNPS Suspend resume issue */ + u8 broken_suspend; }; /* Platform specific overrides to generic XHCI hc_driver ops */