From 253e05724f9230910344357b1142ad8642ff9f5a Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Tue, 27 Oct 2009 15:20:13 -0400 Subject: USB: add a "remove hardware" sysfs attribute This patch (as1297) adds a "remove" attribute to each USB device's directory in sysfs. Writing to this attribute causes the device to be deconfigured (the same as writing 0 to the "bConfigurationValue" attribute) and then tells the hub driver to disable the device's upstream port. The device remains locked during these activities so there is no possibility of it getting reconfigured in between. The port will remain disabled until after the device is unplugged. The purpose of this is to provide a means for user programs to imitate the "Safely remove hardware" applet in Windows. Some devices do expect their ports to be disabled before they are unplugged, and they provide visual feedback to users indicating when they can safely be unplugged. The security implications are minimal. Writing to the "remove" attribute is no more dangerous than writing to the "bConfigurationValue" attribute. Signed-off-by: Alan Stern Cc: David Zeuthen Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/sysfs.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'drivers/usb/core/sysfs.c') diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c index 7ec3041ae79e..470e2413a9cf 100644 --- a/drivers/usb/core/sysfs.c +++ b/drivers/usb/core/sysfs.c @@ -508,6 +508,28 @@ static ssize_t usb_dev_authorized_store(struct device *dev, static DEVICE_ATTR(authorized, 0644, usb_dev_authorized_show, usb_dev_authorized_store); +/* "Safely remove a device" */ +static ssize_t usb_remove_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct usb_device *udev = to_usb_device(dev); + int rc = 0; + + usb_lock_device(udev); + if (udev->state != USB_STATE_NOTATTACHED) { + + /* To avoid races, first unconfigure and then remove */ + usb_set_configuration(udev, -1); + rc = usb_remove_device(udev); + } + if (rc == 0) + rc = count; + usb_unlock_device(udev); + return rc; +} +static DEVICE_ATTR(remove, 0200, NULL, usb_remove_store); + static struct attribute *dev_attrs[] = { /* current configuration's attributes */ @@ -533,6 +555,7 @@ static struct attribute *dev_attrs[] = { &dev_attr_maxchild.attr, &dev_attr_quirks.attr, &dev_attr_authorized.attr, + &dev_attr_remove.attr, NULL, }; static struct attribute_group dev_attr_grp = { -- cgit v1.2.2 From 9af23624ae2c7978313b46e58fdc4ca5d8b799f5 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 30 Nov 2009 11:15:02 -0800 Subject: USB: add devpath sysfs attribute This is not exported from the usb core, yet we rely on it to create paths to interfaces for this device in sysfs. Export it to make userspace tools have an easier time to figure things out. Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/sysfs.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'drivers/usb/core/sysfs.c') diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c index 470e2413a9cf..ae763974be25 100644 --- a/drivers/usb/core/sysfs.c +++ b/drivers/usb/core/sysfs.c @@ -138,6 +138,16 @@ show_devnum(struct device *dev, struct device_attribute *attr, char *buf) } static DEVICE_ATTR(devnum, S_IRUGO, show_devnum, NULL); +static ssize_t +show_devpath(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct usb_device *udev; + + udev = to_usb_device(dev); + return sprintf(buf, "%s\n", udev->devpath); +} +static DEVICE_ATTR(devpath, S_IRUGO, show_devpath, NULL); + static ssize_t show_version(struct device *dev, struct device_attribute *attr, char *buf) { @@ -538,8 +548,8 @@ static struct attribute *dev_attrs[] = { &dev_attr_bConfigurationValue.attr, &dev_attr_bmAttributes.attr, &dev_attr_bMaxPower.attr, - &dev_attr_urbnum.attr, /* device attributes */ + &dev_attr_urbnum.attr, &dev_attr_idVendor.attr, &dev_attr_idProduct.attr, &dev_attr_bcdDevice.attr, @@ -551,6 +561,7 @@ static struct attribute *dev_attrs[] = { &dev_attr_speed.attr, &dev_attr_busnum.attr, &dev_attr_devnum.attr, + &dev_attr_devpath.attr, &dev_attr_version.attr, &dev_attr_maxchild.attr, &dev_attr_quirks.attr, -- cgit v1.2.2 From 8e4ceb38eb5bbaef22fc00abe9bc11e26bea2ab5 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Mon, 7 Dec 2009 13:01:37 -0500 Subject: USB: prepare for changover to Runtime PM framework This patch (as1303) revises the USB Power Management infrastructure to make it compatible with the new driver-model Runtime PM framework: Drivers are no longer allowed to access intf->pm_usage_cnt directly; the PM framework manages its own usage counters. usb_autopm_set_interface() is eliminated, because it directly sets intf->pm_usage_cnt. usb_autopm_enable() and usb_autopm_disable() are eliminated, because they call usb_autopm_set_interface(). usb_autopm_get_interface_no_resume() and usb_autopm_put_interface_no_suspend() are added. They correspond to pm_runtime_get_noresume() and pm_runtime_put_noidle() in the PM framework. The power/level attribute no longer accepts "suspend", only "on" and "auto". The PM framework doesn't allow devices to be forced into a suspended mode. The hub driver contains the only code that violates the new guidelines. It is updated to use the new interface routines instead. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/sysfs.c | 25 ++++--------------------- 1 file changed, 4 insertions(+), 21 deletions(-) (limited to 'drivers/usb/core/sysfs.c') diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c index ae763974be25..15477008b631 100644 --- a/drivers/usb/core/sysfs.c +++ b/drivers/usb/core/sysfs.c @@ -327,7 +327,6 @@ static DEVICE_ATTR(autosuspend, S_IRUGO | S_IWUSR, static const char on_string[] = "on"; static const char auto_string[] = "auto"; -static const char suspend_string[] = "suspend"; static ssize_t show_level(struct device *dev, struct device_attribute *attr, char *buf) @@ -335,13 +334,8 @@ show_level(struct device *dev, struct device_attribute *attr, char *buf) struct usb_device *udev = to_usb_device(dev); const char *p = auto_string; - if (udev->state == USB_STATE_SUSPENDED) { - if (udev->autoresume_disabled) - p = suspend_string; - } else { - if (udev->autosuspend_disabled) - p = on_string; - } + if (udev->state != USB_STATE_SUSPENDED && udev->autosuspend_disabled) + p = on_string; return sprintf(buf, "%s\n", p); } @@ -353,7 +347,7 @@ set_level(struct device *dev, struct device_attribute *attr, int len = count; char *cp; int rc = 0; - int old_autosuspend_disabled, old_autoresume_disabled; + int old_autosuspend_disabled; cp = memchr(buf, '\n', count); if (cp) @@ -361,7 +355,6 @@ set_level(struct device *dev, struct device_attribute *attr, usb_lock_device(udev); old_autosuspend_disabled = udev->autosuspend_disabled; - old_autoresume_disabled = udev->autoresume_disabled; /* Setting the flags without calling usb_pm_lock is a subject to * races, but who cares... @@ -369,28 +362,18 @@ set_level(struct device *dev, struct device_attribute *attr, if (len == sizeof on_string - 1 && strncmp(buf, on_string, len) == 0) { udev->autosuspend_disabled = 1; - udev->autoresume_disabled = 0; rc = usb_external_resume_device(udev, PMSG_USER_RESUME); } else if (len == sizeof auto_string - 1 && strncmp(buf, auto_string, len) == 0) { udev->autosuspend_disabled = 0; - udev->autoresume_disabled = 0; rc = usb_external_resume_device(udev, PMSG_USER_RESUME); - } else if (len == sizeof suspend_string - 1 && - strncmp(buf, suspend_string, len) == 0) { - udev->autosuspend_disabled = 0; - udev->autoresume_disabled = 1; - rc = usb_external_suspend_device(udev, PMSG_USER_SUSPEND); - } else rc = -EINVAL; - if (rc) { + if (rc) udev->autosuspend_disabled = old_autosuspend_disabled; - udev->autoresume_disabled = old_autoresume_disabled; - } usb_unlock_device(udev); return (rc < 0 ? rc : count); } -- cgit v1.2.2