From patchwork Mon May 28 06:32:18 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Boichat X-Patchwork-Id: 10429817 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 B696260327 for ; Mon, 28 May 2018 06:33:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A699728963 for ; Mon, 28 May 2018 06:33:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9900F28AAF; Mon, 28 May 2018 06:33:48 +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=-7.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI, T_DKIM_INVALID autolearn=unavailable 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 DC27328963 for ; Mon, 28 May 2018 06:33:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753366AbeE1GdF (ORCPT ); Mon, 28 May 2018 02:33:05 -0400 Received: from mail-pl0-f66.google.com ([209.85.160.66]:36081 "EHLO mail-pl0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753310AbeE1GdE (ORCPT ); Mon, 28 May 2018 02:33:04 -0400 Received: by mail-pl0-f66.google.com with SMTP id v24-v6so6625548plo.3 for ; Sun, 27 May 2018 23:33:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id; bh=oCKoxcoys5U4s+10yUMCd4wM1xS5rCNwihYiCYLvijE=; b=AFNDjdY42IFbFP2H/zMjVE1xA84HIveS8yAxQ5ngXsTCpktB1LKS56bOBRQwXI+0Im 4RG39Iv3PAvUkXSHOCHMMVSIZAibWDvkUw68aRew25WVnGSCttZOOm9yNbOa5VYbgL5s WPSg+zlindwcoMahCu0qptMmkrEm5jezUjqD8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=oCKoxcoys5U4s+10yUMCd4wM1xS5rCNwihYiCYLvijE=; b=oLdd0sUW09EpEREK0/ZTDXT7+px6fEeXUwDm+Q2hdpaatnECofcY0yepF01oJuINfQ Rm9iSt1GaQEUbRzkcIAT92f1nknFR+cQs+hcPOSzRuZzYV8uT2Q1xzUxLwh9dDbaBYfH LPIOlSQ5d0DxDce9CYFkObDzJiifJQMGEXqeBOKTeUX3bVVUVChqiHYBYHo8GFWs3Mw0 BAAG36Ur4+6U/9PF5rCf9EGfZdBLzNcEmxXvllDK6Luq6WMhHILQMNBA/PA31AK3qh20 tgwjmP2ebHRkPhrmK95h92jrlG4rawIbLlBnlazuOMb5FncDcEpxBwmNV540jzQJOoQi 3TZQ== X-Gm-Message-State: ALKqPweF211M0dsVo/lE3YRF+t89OaNkIDmQ8qbvwI8QSA+toTRsmVW3 KZ28NmA++c8HfT4fQy+nFwuf1Q== X-Google-Smtp-Source: AB8JxZrjd+1SyLZQq13EBSo5KDU8Tc2n+KwVWr4Z/AWSaeN9PZn8thk54xzD8diWRaLHcyvPxYWYAg== X-Received: by 2002:a17:902:4081:: with SMTP id c1-v6mr12342802pld.60.1527489183398; Sun, 27 May 2018 23:33:03 -0700 (PDT) Received: from drinkcat.tpe.corp.google.com ([2401:fa00:1:b:9ba:cd16:d555:bacf]) by smtp.gmail.com with ESMTPSA id y2-v6sm36431247pgp.92.2018.05.27.23.33.00 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 27 May 2018 23:33:02 -0700 (PDT) From: Nicolas Boichat To: Greg Kroah-Hartman Cc: Alan Stern , Mathias Nyman , Felipe Balbi , Eugene Korenevsky , Peter Chen , Daniel Drake , Joe Perches , Nicolas Boichat , Johan Hovold , Richard Leitner , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, groeck@chromium.org Subject: [PATCHv2 1/2] usb: hub: Per-port setting to use old enumeration scheme Date: Mon, 28 May 2018 14:32:18 +0800 Message-Id: <20180528063219.234757-1-drinkcat@chromium.org> X-Mailer: git-send-email 2.17.0.921.gf22659ad46-goog 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 The "old" enumeration scheme is considerably faster (it takes ~244ms instead of ~356ms to get the descriptor). It is currently only possible to use the old scheme globally (/sys/module/usbcore/parameters/old_scheme_first), which is not desirable as the new scheme was introduced to increase compatibility with more devices. However, in our case, we care about time-to-active for a specific USB device (which we make the firmware for), on a specific port (that is pogo-pin based: not a standard USB port). This new sysfs option makes it possible to use the old scheme on a single port only. Signed-off-by: Nicolas Boichat --- Changes since v1: - Added documentation in Documentation/ABI - Updated timing in commit message to account for recent improvement in USB core (74072bae88fb3b) Documentation/ABI/testing/sysfs-bus-usb | 18 ++++++++++++++++++ drivers/usb/core/hub.c | 13 +++++++++---- drivers/usb/core/hub.h | 1 + drivers/usb/core/port.c | 23 +++++++++++++++++++++++ include/linux/usb.h | 7 +++++++ 5 files changed, 58 insertions(+), 4 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb index c6e9b30f05b13..a31a66d62cbba 100644 --- a/Documentation/ABI/testing/sysfs-bus-usb +++ b/Documentation/ABI/testing/sysfs-bus-usb @@ -189,6 +189,24 @@ Description: The file will read "hotplug", "wired" and "not used" if the information is available, and "unknown" otherwise. +What: /sys/bus/usb/devices/.../(hub interface)/portX/quirks +Date: May 2018 +Contact: Nicolas Boichat +Description: + In some cases, we care about time-to-active for devices + connected on a specific port (e.g. non-standard USB port like + pogo pins), where the device to be connected is known in + advance, and behaves well according to the specification. + This attribute is a bit-field that controls the behavior of + a specific port: + - Bit 0 of this field selects the "old" enumeration scheme, + as it is considerably faster (it only causes one USB reset + instead of 2). + The old enumeration scheme can also be selected globally + using /sys/module/usbcore/parameters/old_scheme_first, but + it is often not desirable as the new scheme was introduced to + increase compatibility with more devices. + What: /sys/bus/usb/devices/.../(hub interface)/portX/over_current_count Date: February 2018 Contact: Richard Leitner diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index c2d993d3816f0..f900f66a62856 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2636,7 +2636,7 @@ static unsigned hub_is_wusb(struct usb_hub *hub) #define SET_ADDRESS_TRIES 2 #define GET_DESCRIPTOR_TRIES 2 #define SET_CONFIG_TRIES (2 * (use_both_schemes + 1)) -#define USE_NEW_SCHEME(i) ((i) / 2 == (int)old_scheme_first) +#define USE_NEW_SCHEME(i, scheme) ((i) / 2 == (int)scheme) #define HUB_ROOT_RESET_TIME 60 /* times are in msec */ #define HUB_SHORT_RESET_TIME 10 @@ -2651,12 +2651,16 @@ static unsigned hub_is_wusb(struct usb_hub *hub) * enumeration failures, so disable this enumeration scheme for USB3 * devices. */ -static bool use_new_scheme(struct usb_device *udev, int retry) +static bool use_new_scheme(struct usb_device *udev, int retry, + struct usb_port *port_dev) { + int old_scheme_first_port = + port_dev->quirks & USB_PORT_QUIRK_OLD_SCHEME; + if (udev->speed >= USB_SPEED_SUPER) return false; - return USE_NEW_SCHEME(retry); + return USE_NEW_SCHEME(retry, old_scheme_first_port || old_scheme_first); } /* Is a USB 3.0 port in the Inactive or Compliance Mode state? @@ -4392,6 +4396,7 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1, { struct usb_device *hdev = hub->hdev; struct usb_hcd *hcd = bus_to_hcd(hdev->bus); + struct usb_port *port_dev = hub->ports[port1 - 1]; int retries, operations, retval, i; unsigned delay = HUB_SHORT_RESET_TIME; enum usb_device_speed oldspeed = udev->speed; @@ -4513,7 +4518,7 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1, for (retries = 0; retries < GET_DESCRIPTOR_TRIES; (++retries, msleep(100))) { bool did_new_scheme = false; - if (use_new_scheme(udev, retry_counter)) { + if (use_new_scheme(udev, retry_counter, port_dev)) { struct usb_device_descriptor *buf; int r = 0; diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h index 4dc769ee9c740..4accfb63f7dcb 100644 --- a/drivers/usb/core/hub.h +++ b/drivers/usb/core/hub.h @@ -98,6 +98,7 @@ struct usb_port { struct mutex status_lock; u32 over_current_count; u8 portnum; + u32 quirks; unsigned int is_superspeed:1; unsigned int usb3_lpm_u1_permit:1; unsigned int usb3_lpm_u2_permit:1; diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c index 6979bde87d310..4a21431953953 100644 --- a/drivers/usb/core/port.c +++ b/drivers/usb/core/port.c @@ -50,6 +50,28 @@ static ssize_t over_current_count_show(struct device *dev, } static DEVICE_ATTR_RO(over_current_count); +static ssize_t quirks_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct usb_port *port_dev = to_usb_port(dev); + + return sprintf(buf, "%08x\n", port_dev->quirks); +} + +static ssize_t quirks_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct usb_port *port_dev = to_usb_port(dev); + u32 value; + + if (kstrtou32(buf, 16, &value)) + return -EINVAL; + + port_dev->quirks = value; + return count; +} +static DEVICE_ATTR_RW(quirks); + static ssize_t usb3_lpm_permit_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -118,6 +140,7 @@ static DEVICE_ATTR_RW(usb3_lpm_permit); static struct attribute *port_dev_attrs[] = { &dev_attr_connect_type.attr, + &dev_attr_quirks.attr, &dev_attr_over_current_count.attr, NULL, }; diff --git a/include/linux/usb.h b/include/linux/usb.h index beffceec49158..2ade17992ed66 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -489,6 +489,13 @@ enum usb_port_connect_type { USB_PORT_NOT_USED, }; +/* + * USB port quirks. + */ + +/* For the given port, prefer the old (faster) enumeration scheme. */ +#define USB_PORT_QUIRK_OLD_SCHEME BIT(0) + /* * USB 2.0 Link Power Management (LPM) parameters. */