linux/drivers/usb/core/sysfs.c
Sarah Sharp de68bab4fa usb: Don't enable USB 2.0 Link PM by default.
How it's supposed to work:
--------------------------

USB 2.0 Link PM is a lower power state that some newer USB 2.0 devices
support.  USB 3.0 devices certified by the USB-IF are required to
support it if they are plugged into a USB 2.0 only port, or a USB 2.0
cable is used.  USB 2.0 Link PM requires both a USB device and a host
controller that supports USB 2.0 hardware-enabled LPM.

USB 2.0 Link PM is designed to be enabled once by software, and the host
hardware handles transitions to the L1 state automatically.  The premise
of USB 2.0 Link PM is to be able to put the device into a lower power
link state when the bus is idle or the device NAKs USB IN transfers for
a specified amount of time.

...but hardware is broken:
--------------------------

It turns out many USB 3.0 devices claim to support USB 2.0 Link PM (by
setting the LPM bit in their USB 2.0 BOS descriptor), but they don't
actually implement it correctly.  This manifests as the USB device
refusing to respond to transfers when it is plugged into a USB 2.0 only
port under the Haswell-ULT/Lynx Point LP xHCI host.

These devices pass the xHCI driver's simple test to enable USB 2.0 Link
PM, wait for the port to enter L1, and then bring it back into L0.  They
only start to break when L1 entry is interleaved with transfers.

Some devices then fail to respond to the next control transfer (usually
a Set Configuration).  This results in devices never enumerating.

Other mass storage devices (such as a later model Western Digital My
Passport USB 3.0 hard drive) respond fine to going into L1 between
control transfers.  They ACK the entry, come out of L1 when the host
needs to send a control transfer, and respond properly to those control
transfers.  However, when the first READ10 SCSI command is sent, the
device NAKs the data phase while it's reading from the spinning disk.
Eventually, the host requests to put the link into L1, and the device
ACKs that request.  Then it never responds to the data phase of the
READ10 command.  This results in not being able to read from the drive.

Some mass storage devices (like the Corsair Survivor USB 3.0 flash
drive) are well behaved.  They ACK the entry into L1 during control
transfers, and when SCSI commands start coming in, they NAK the requests
to go into L1, because they need to be at full power.

Not all USB 3.0 devices advertise USB 2.0 link PM support.  My Point
Grey USB 3.0 webcam advertises itself as a USB 2.1 device, but doesn't
have a USB 2.0 BOS descriptor, so we don't enable USB 2.0 Link PM.  I
suspect that means the device isn't certified.

What do we do about it?
-----------------------

There's really no good way for the kernel to test these devices.
Therefore, the kernel needs to disable USB 2.0 Link PM by default, and
distros will have to enable it by writing 1 to the sysfs file
/sys/bus/usb/devices/../power/usb2_hardware_lpm.  Rip out the xHCI Link
PM test, since it's not sufficient to detect these buggy devices, and
don't automatically enable LPM after the device is addressed.

This patch should be backported to kernels as old as 3.11, that
contain the commit a558ccdcc7 "usb: xhci:
add USB2 Link power management BESL support".  Without this fix, some
USB 3.0 devices will not enumerate or work properly under USB 2.0 ports
on Haswell-ULT systems.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org
2013-10-16 12:24:19 -07:00

1003 lines
25 KiB
C

/*
* drivers/usb/core/sysfs.c
*
* (C) Copyright 2002 David Brownell
* (C) Copyright 2002,2004 Greg Kroah-Hartman
* (C) Copyright 2002,2004 IBM Corp.
*
* All of the sysfs file attributes for usb devices and interfaces.
*
*/
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/usb.h>
#include <linux/usb/quirks.h>
#include "usb.h"
/* Active configuration fields */
#define usb_actconfig_show(field, format_string) \
static ssize_t field##_show(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ \
struct usb_device *udev; \
struct usb_host_config *actconfig; \
ssize_t rc = 0; \
\
udev = to_usb_device(dev); \
usb_lock_device(udev); \
actconfig = udev->actconfig; \
if (actconfig) \
rc = sprintf(buf, format_string, \
actconfig->desc.field); \
usb_unlock_device(udev); \
return rc; \
} \
#define usb_actconfig_attr(field, format_string) \
usb_actconfig_show(field, format_string) \
static DEVICE_ATTR_RO(field)
usb_actconfig_attr(bNumInterfaces, "%2d\n");
usb_actconfig_attr(bmAttributes, "%2x\n");
static ssize_t bMaxPower_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_device *udev;
struct usb_host_config *actconfig;
ssize_t rc = 0;
udev = to_usb_device(dev);
usb_lock_device(udev);
actconfig = udev->actconfig;
if (actconfig)
rc = sprintf(buf, "%dmA\n", usb_get_max_power(udev, actconfig));
usb_unlock_device(udev);
return rc;
}
static DEVICE_ATTR_RO(bMaxPower);
static ssize_t configuration_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_device *udev;
struct usb_host_config *actconfig;
ssize_t rc = 0;
udev = to_usb_device(dev);
usb_lock_device(udev);
actconfig = udev->actconfig;
if (actconfig && actconfig->string)
rc = sprintf(buf, "%s\n", actconfig->string);
usb_unlock_device(udev);
return rc;
}
static DEVICE_ATTR_RO(configuration);
/* configuration value is always present, and r/w */
usb_actconfig_show(bConfigurationValue, "%u\n");
static ssize_t bConfigurationValue_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct usb_device *udev = to_usb_device(dev);
int config, value;
if (sscanf(buf, "%d", &config) != 1 || config < -1 || config > 255)
return -EINVAL;
usb_lock_device(udev);
value = usb_set_configuration(udev, config);
usb_unlock_device(udev);
return (value < 0) ? value : count;
}
static DEVICE_ATTR_IGNORE_LOCKDEP(bConfigurationValue, S_IRUGO | S_IWUSR,
bConfigurationValue_show, bConfigurationValue_store);
/* String fields */
#define usb_string_attr(name) \
static ssize_t name##_show(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ \
struct usb_device *udev; \
int retval; \
\
udev = to_usb_device(dev); \
usb_lock_device(udev); \
retval = sprintf(buf, "%s\n", udev->name); \
usb_unlock_device(udev); \
return retval; \
} \
static DEVICE_ATTR_RO(name)
usb_string_attr(product);
usb_string_attr(manufacturer);
usb_string_attr(serial);
static ssize_t speed_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct usb_device *udev;
char *speed;
udev = to_usb_device(dev);
switch (udev->speed) {
case USB_SPEED_LOW:
speed = "1.5";
break;
case USB_SPEED_UNKNOWN:
case USB_SPEED_FULL:
speed = "12";
break;
case USB_SPEED_HIGH:
speed = "480";
break;
case USB_SPEED_WIRELESS:
speed = "480";
break;
case USB_SPEED_SUPER:
speed = "5000";
break;
default:
speed = "unknown";
}
return sprintf(buf, "%s\n", speed);
}
static DEVICE_ATTR_RO(speed);
static ssize_t busnum_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct usb_device *udev;
udev = to_usb_device(dev);
return sprintf(buf, "%d\n", udev->bus->busnum);
}
static DEVICE_ATTR_RO(busnum);
static ssize_t devnum_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct usb_device *udev;
udev = to_usb_device(dev);
return sprintf(buf, "%d\n", udev->devnum);
}
static DEVICE_ATTR_RO(devnum);
static ssize_t devpath_show(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_RO(devpath);
static ssize_t version_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct usb_device *udev;
u16 bcdUSB;
udev = to_usb_device(dev);
bcdUSB = le16_to_cpu(udev->descriptor.bcdUSB);
return sprintf(buf, "%2x.%02x\n", bcdUSB >> 8, bcdUSB & 0xff);
}
static DEVICE_ATTR_RO(version);
static ssize_t maxchild_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct usb_device *udev;
udev = to_usb_device(dev);
return sprintf(buf, "%d\n", udev->maxchild);
}
static DEVICE_ATTR_RO(maxchild);
static ssize_t quirks_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct usb_device *udev;
udev = to_usb_device(dev);
return sprintf(buf, "0x%x\n", udev->quirks);
}
static DEVICE_ATTR_RO(quirks);
static ssize_t avoid_reset_quirk_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_device *udev;
udev = to_usb_device(dev);
return sprintf(buf, "%d\n", !!(udev->quirks & USB_QUIRK_RESET));
}
static ssize_t avoid_reset_quirk_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct usb_device *udev = to_usb_device(dev);
int val;
if (sscanf(buf, "%d", &val) != 1 || val < 0 || val > 1)
return -EINVAL;
usb_lock_device(udev);
if (val)
udev->quirks |= USB_QUIRK_RESET;
else
udev->quirks &= ~USB_QUIRK_RESET;
usb_unlock_device(udev);
return count;
}
static DEVICE_ATTR_RW(avoid_reset_quirk);
static ssize_t urbnum_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct usb_device *udev;
udev = to_usb_device(dev);
return sprintf(buf, "%d\n", atomic_read(&udev->urbnum));
}
static DEVICE_ATTR_RO(urbnum);
static ssize_t removable_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct usb_device *udev;
char *state;
udev = to_usb_device(dev);
switch (udev->removable) {
case USB_DEVICE_REMOVABLE:
state = "removable";
break;
case USB_DEVICE_FIXED:
state = "fixed";
break;
default:
state = "unknown";
}
return sprintf(buf, "%s\n", state);
}
static DEVICE_ATTR_RO(removable);
static ssize_t ltm_capable_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
if (usb_device_supports_ltm(to_usb_device(dev)))
return sprintf(buf, "%s\n", "yes");
return sprintf(buf, "%s\n", "no");
}
static DEVICE_ATTR_RO(ltm_capable);
#ifdef CONFIG_PM
static ssize_t persist_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct usb_device *udev = to_usb_device(dev);
return sprintf(buf, "%d\n", udev->persist_enabled);
}
static ssize_t persist_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct usb_device *udev = to_usb_device(dev);
int value;
/* Hubs are always enabled for USB_PERSIST */
if (udev->descriptor.bDeviceClass == USB_CLASS_HUB)
return -EPERM;
if (sscanf(buf, "%d", &value) != 1)
return -EINVAL;
usb_lock_device(udev);
udev->persist_enabled = !!value;
usb_unlock_device(udev);
return count;
}
static DEVICE_ATTR_RW(persist);
static int add_persist_attributes(struct device *dev)
{
int rc = 0;
if (is_usb_device(dev)) {
struct usb_device *udev = to_usb_device(dev);
/* Hubs are automatically enabled for USB_PERSIST,
* no point in creating the attribute file.
*/
if (udev->descriptor.bDeviceClass != USB_CLASS_HUB)
rc = sysfs_add_file_to_group(&dev->kobj,
&dev_attr_persist.attr,
power_group_name);
}
return rc;
}
static void remove_persist_attributes(struct device *dev)
{
sysfs_remove_file_from_group(&dev->kobj,
&dev_attr_persist.attr,
power_group_name);
}
#else
#define add_persist_attributes(dev) 0
#define remove_persist_attributes(dev) do {} while (0)
#endif /* CONFIG_PM */
#ifdef CONFIG_PM_RUNTIME
static ssize_t connected_duration_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_device *udev = to_usb_device(dev);
return sprintf(buf, "%u\n",
jiffies_to_msecs(jiffies - udev->connect_time));
}
static DEVICE_ATTR_RO(connected_duration);
/*
* If the device is resumed, the last time the device was suspended has
* been pre-subtracted from active_duration. We add the current time to
* get the duration that the device was actually active.
*
* If the device is suspended, the active_duration is up-to-date.
*/
static ssize_t active_duration_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_device *udev = to_usb_device(dev);
int duration;
if (udev->state != USB_STATE_SUSPENDED)
duration = jiffies_to_msecs(jiffies + udev->active_duration);
else
duration = jiffies_to_msecs(udev->active_duration);
return sprintf(buf, "%u\n", duration);
}
static DEVICE_ATTR_RO(active_duration);
static ssize_t autosuspend_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "%d\n", dev->power.autosuspend_delay / 1000);
}
static ssize_t autosuspend_store(struct device *dev,
struct device_attribute *attr, const char *buf,
size_t count)
{
int value;
if (sscanf(buf, "%d", &value) != 1 || value >= INT_MAX/1000 ||
value <= -INT_MAX/1000)
return -EINVAL;
pm_runtime_set_autosuspend_delay(dev, value * 1000);
return count;
}
static DEVICE_ATTR_RW(autosuspend);
static const char on_string[] = "on";
static const char auto_string[] = "auto";
static void warn_level(void)
{
static int level_warned;
if (!level_warned) {
level_warned = 1;
printk(KERN_WARNING "WARNING! power/level is deprecated; "
"use power/control instead\n");
}
}
static ssize_t level_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct usb_device *udev = to_usb_device(dev);
const char *p = auto_string;
warn_level();
if (udev->state != USB_STATE_SUSPENDED && !udev->dev.power.runtime_auto)
p = on_string;
return sprintf(buf, "%s\n", p);
}
static ssize_t level_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct usb_device *udev = to_usb_device(dev);
int len = count;
char *cp;
int rc = count;
warn_level();
cp = memchr(buf, '\n', count);
if (cp)
len = cp - buf;
usb_lock_device(udev);
if (len == sizeof on_string - 1 &&
strncmp(buf, on_string, len) == 0)
usb_disable_autosuspend(udev);
else if (len == sizeof auto_string - 1 &&
strncmp(buf, auto_string, len) == 0)
usb_enable_autosuspend(udev);
else
rc = -EINVAL;
usb_unlock_device(udev);
return rc;
}
static DEVICE_ATTR_RW(level);
static ssize_t usb2_hardware_lpm_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_device *udev = to_usb_device(dev);
const char *p;
if (udev->usb2_hw_lpm_allowed == 1)
p = "enabled";
else
p = "disabled";
return sprintf(buf, "%s\n", p);
}
static ssize_t usb2_hardware_lpm_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct usb_device *udev = to_usb_device(dev);
bool value;
int ret;
usb_lock_device(udev);
ret = strtobool(buf, &value);
if (!ret) {
udev->usb2_hw_lpm_allowed = value;
ret = usb_set_usb2_hardware_lpm(udev, value);
}
usb_unlock_device(udev);
if (!ret)
return count;
return ret;
}
static DEVICE_ATTR_RW(usb2_hardware_lpm);
static ssize_t usb2_lpm_l1_timeout_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct usb_device *udev = to_usb_device(dev);
return sprintf(buf, "%d\n", udev->l1_params.timeout);
}
static ssize_t usb2_lpm_l1_timeout_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct usb_device *udev = to_usb_device(dev);
u16 timeout;
if (kstrtou16(buf, 0, &timeout))
return -EINVAL;
udev->l1_params.timeout = timeout;
return count;
}
static DEVICE_ATTR_RW(usb2_lpm_l1_timeout);
static ssize_t usb2_lpm_besl_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_device *udev = to_usb_device(dev);
return sprintf(buf, "%d\n", udev->l1_params.besl);
}
static ssize_t usb2_lpm_besl_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct usb_device *udev = to_usb_device(dev);
u8 besl;
if (kstrtou8(buf, 0, &besl) || besl > 15)
return -EINVAL;
udev->l1_params.besl = besl;
return count;
}
static DEVICE_ATTR_RW(usb2_lpm_besl);
static struct attribute *usb2_hardware_lpm_attr[] = {
&dev_attr_usb2_hardware_lpm.attr,
&dev_attr_usb2_lpm_l1_timeout.attr,
&dev_attr_usb2_lpm_besl.attr,
NULL,
};
static struct attribute_group usb2_hardware_lpm_attr_group = {
.name = power_group_name,
.attrs = usb2_hardware_lpm_attr,
};
static struct attribute *power_attrs[] = {
&dev_attr_autosuspend.attr,
&dev_attr_level.attr,
&dev_attr_connected_duration.attr,
&dev_attr_active_duration.attr,
NULL,
};
static struct attribute_group power_attr_group = {
.name = power_group_name,
.attrs = power_attrs,
};
static int add_power_attributes(struct device *dev)
{
int rc = 0;
if (is_usb_device(dev)) {
struct usb_device *udev = to_usb_device(dev);
rc = sysfs_merge_group(&dev->kobj, &power_attr_group);
if (udev->usb2_hw_lpm_capable == 1)
rc = sysfs_merge_group(&dev->kobj,
&usb2_hardware_lpm_attr_group);
}
return rc;
}
static void remove_power_attributes(struct device *dev)
{
sysfs_unmerge_group(&dev->kobj, &usb2_hardware_lpm_attr_group);
sysfs_unmerge_group(&dev->kobj, &power_attr_group);
}
#else
#define add_power_attributes(dev) 0
#define remove_power_attributes(dev) do {} while (0)
#endif /* CONFIG_PM_RUNTIME */
/* Descriptor fields */
#define usb_descriptor_attr_le16(field, format_string) \
static ssize_t \
field##_show(struct device *dev, struct device_attribute *attr, \
char *buf) \
{ \
struct usb_device *udev; \
\
udev = to_usb_device(dev); \
return sprintf(buf, format_string, \
le16_to_cpu(udev->descriptor.field)); \
} \
static DEVICE_ATTR_RO(field)
usb_descriptor_attr_le16(idVendor, "%04x\n");
usb_descriptor_attr_le16(idProduct, "%04x\n");
usb_descriptor_attr_le16(bcdDevice, "%04x\n");
#define usb_descriptor_attr(field, format_string) \
static ssize_t \
field##_show(struct device *dev, struct device_attribute *attr, \
char *buf) \
{ \
struct usb_device *udev; \
\
udev = to_usb_device(dev); \
return sprintf(buf, format_string, udev->descriptor.field); \
} \
static DEVICE_ATTR_RO(field)
usb_descriptor_attr(bDeviceClass, "%02x\n");
usb_descriptor_attr(bDeviceSubClass, "%02x\n");
usb_descriptor_attr(bDeviceProtocol, "%02x\n");
usb_descriptor_attr(bNumConfigurations, "%d\n");
usb_descriptor_attr(bMaxPacketSize0, "%d\n");
/* show if the device is authorized (1) or not (0) */
static ssize_t authorized_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_device *usb_dev = to_usb_device(dev);
return snprintf(buf, PAGE_SIZE, "%u\n", usb_dev->authorized);
}
/*
* Authorize a device to be used in the system
*
* Writing a 0 deauthorizes the device, writing a 1 authorizes it.
*/
static ssize_t authorized_store(struct device *dev,
struct device_attribute *attr, const char *buf,
size_t size)
{
ssize_t result;
struct usb_device *usb_dev = to_usb_device(dev);
unsigned val;
result = sscanf(buf, "%u\n", &val);
if (result != 1)
result = -EINVAL;
else if (val == 0)
result = usb_deauthorize_device(usb_dev);
else
result = usb_authorize_device(usb_dev);
return result < 0 ? result : size;
}
static DEVICE_ATTR_IGNORE_LOCKDEP(authorized, S_IRUGO | S_IWUSR,
authorized_show, authorized_store);
/* "Safely remove a device" */
static ssize_t 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_IGNORE_LOCKDEP(remove, S_IWUSR, NULL, remove_store);
static struct attribute *dev_attrs[] = {
/* current configuration's attributes */
&dev_attr_configuration.attr,
&dev_attr_bNumInterfaces.attr,
&dev_attr_bConfigurationValue.attr,
&dev_attr_bmAttributes.attr,
&dev_attr_bMaxPower.attr,
/* device attributes */
&dev_attr_urbnum.attr,
&dev_attr_idVendor.attr,
&dev_attr_idProduct.attr,
&dev_attr_bcdDevice.attr,
&dev_attr_bDeviceClass.attr,
&dev_attr_bDeviceSubClass.attr,
&dev_attr_bDeviceProtocol.attr,
&dev_attr_bNumConfigurations.attr,
&dev_attr_bMaxPacketSize0.attr,
&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,
&dev_attr_avoid_reset_quirk.attr,
&dev_attr_authorized.attr,
&dev_attr_remove.attr,
&dev_attr_removable.attr,
&dev_attr_ltm_capable.attr,
NULL,
};
static struct attribute_group dev_attr_grp = {
.attrs = dev_attrs,
};
/* When modifying this list, be sure to modify dev_string_attrs_are_visible()
* accordingly.
*/
static struct attribute *dev_string_attrs[] = {
&dev_attr_manufacturer.attr,
&dev_attr_product.attr,
&dev_attr_serial.attr,
NULL
};
static umode_t dev_string_attrs_are_visible(struct kobject *kobj,
struct attribute *a, int n)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct usb_device *udev = to_usb_device(dev);
if (a == &dev_attr_manufacturer.attr) {
if (udev->manufacturer == NULL)
return 0;
} else if (a == &dev_attr_product.attr) {
if (udev->product == NULL)
return 0;
} else if (a == &dev_attr_serial.attr) {
if (udev->serial == NULL)
return 0;
}
return a->mode;
}
static struct attribute_group dev_string_attr_grp = {
.attrs = dev_string_attrs,
.is_visible = dev_string_attrs_are_visible,
};
const struct attribute_group *usb_device_groups[] = {
&dev_attr_grp,
&dev_string_attr_grp,
NULL
};
/* Binary descriptors */
static ssize_t
read_descriptors(struct file *filp, struct kobject *kobj,
struct bin_attribute *attr,
char *buf, loff_t off, size_t count)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct usb_device *udev = to_usb_device(dev);
size_t nleft = count;
size_t srclen, n;
int cfgno;
void *src;
/* The binary attribute begins with the device descriptor.
* Following that are the raw descriptor entries for all the
* configurations (config plus subsidiary descriptors).
*/
usb_lock_device(udev);
for (cfgno = -1; cfgno < udev->descriptor.bNumConfigurations &&
nleft > 0; ++cfgno) {
if (cfgno < 0) {
src = &udev->descriptor;
srclen = sizeof(struct usb_device_descriptor);
} else {
src = udev->rawdescriptors[cfgno];
srclen = __le16_to_cpu(udev->config[cfgno].desc.
wTotalLength);
}
if (off < srclen) {
n = min(nleft, srclen - (size_t) off);
memcpy(buf, src + off, n);
nleft -= n;
buf += n;
off = 0;
} else {
off -= srclen;
}
}
usb_unlock_device(udev);
return count - nleft;
}
static struct bin_attribute dev_bin_attr_descriptors = {
.attr = {.name = "descriptors", .mode = 0444},
.read = read_descriptors,
.size = 18 + 65535, /* dev descr + max-size raw descriptor */
};
int usb_create_sysfs_dev_files(struct usb_device *udev)
{
struct device *dev = &udev->dev;
int retval;
retval = device_create_bin_file(dev, &dev_bin_attr_descriptors);
if (retval)
goto error;
retval = add_persist_attributes(dev);
if (retval)
goto error;
retval = add_power_attributes(dev);
if (retval)
goto error;
return retval;
error:
usb_remove_sysfs_dev_files(udev);
return retval;
}
void usb_remove_sysfs_dev_files(struct usb_device *udev)
{
struct device *dev = &udev->dev;
remove_power_attributes(dev);
remove_persist_attributes(dev);
device_remove_bin_file(dev, &dev_bin_attr_descriptors);
}
/* Interface Accociation Descriptor fields */
#define usb_intf_assoc_attr(field, format_string) \
static ssize_t \
iad_##field##_show(struct device *dev, struct device_attribute *attr, \
char *buf) \
{ \
struct usb_interface *intf = to_usb_interface(dev); \
\
return sprintf(buf, format_string, \
intf->intf_assoc->field); \
} \
static DEVICE_ATTR_RO(iad_##field)
usb_intf_assoc_attr(bFirstInterface, "%02x\n");
usb_intf_assoc_attr(bInterfaceCount, "%02d\n");
usb_intf_assoc_attr(bFunctionClass, "%02x\n");
usb_intf_assoc_attr(bFunctionSubClass, "%02x\n");
usb_intf_assoc_attr(bFunctionProtocol, "%02x\n");
/* Interface fields */
#define usb_intf_attr(field, format_string) \
static ssize_t \
field##_show(struct device *dev, struct device_attribute *attr, \
char *buf) \
{ \
struct usb_interface *intf = to_usb_interface(dev); \
\
return sprintf(buf, format_string, \
intf->cur_altsetting->desc.field); \
} \
static DEVICE_ATTR_RO(field)
usb_intf_attr(bInterfaceNumber, "%02x\n");
usb_intf_attr(bAlternateSetting, "%2d\n");
usb_intf_attr(bNumEndpoints, "%02x\n");
usb_intf_attr(bInterfaceClass, "%02x\n");
usb_intf_attr(bInterfaceSubClass, "%02x\n");
usb_intf_attr(bInterfaceProtocol, "%02x\n");
static ssize_t interface_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct usb_interface *intf;
char *string;
intf = to_usb_interface(dev);
string = ACCESS_ONCE(intf->cur_altsetting->string);
if (!string)
return 0;
return sprintf(buf, "%s\n", string);
}
static DEVICE_ATTR_RO(interface);
static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct usb_interface *intf;
struct usb_device *udev;
struct usb_host_interface *alt;
intf = to_usb_interface(dev);
udev = interface_to_usbdev(intf);
alt = ACCESS_ONCE(intf->cur_altsetting);
return sprintf(buf, "usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02X"
"ic%02Xisc%02Xip%02Xin%02X\n",
le16_to_cpu(udev->descriptor.idVendor),
le16_to_cpu(udev->descriptor.idProduct),
le16_to_cpu(udev->descriptor.bcdDevice),
udev->descriptor.bDeviceClass,
udev->descriptor.bDeviceSubClass,
udev->descriptor.bDeviceProtocol,
alt->desc.bInterfaceClass,
alt->desc.bInterfaceSubClass,
alt->desc.bInterfaceProtocol,
alt->desc.bInterfaceNumber);
}
static DEVICE_ATTR_RO(modalias);
static ssize_t supports_autosuspend_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int s;
device_lock(dev);
/* Devices will be autosuspended even when an interface isn't claimed */
s = (!dev->driver || to_usb_driver(dev->driver)->supports_autosuspend);
device_unlock(dev);
return sprintf(buf, "%u\n", s);
}
static DEVICE_ATTR_RO(supports_autosuspend);
static struct attribute *intf_attrs[] = {
&dev_attr_bInterfaceNumber.attr,
&dev_attr_bAlternateSetting.attr,
&dev_attr_bNumEndpoints.attr,
&dev_attr_bInterfaceClass.attr,
&dev_attr_bInterfaceSubClass.attr,
&dev_attr_bInterfaceProtocol.attr,
&dev_attr_modalias.attr,
&dev_attr_supports_autosuspend.attr,
NULL,
};
static struct attribute_group intf_attr_grp = {
.attrs = intf_attrs,
};
static struct attribute *intf_assoc_attrs[] = {
&dev_attr_iad_bFirstInterface.attr,
&dev_attr_iad_bInterfaceCount.attr,
&dev_attr_iad_bFunctionClass.attr,
&dev_attr_iad_bFunctionSubClass.attr,
&dev_attr_iad_bFunctionProtocol.attr,
NULL,
};
static umode_t intf_assoc_attrs_are_visible(struct kobject *kobj,
struct attribute *a, int n)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct usb_interface *intf = to_usb_interface(dev);
if (intf->intf_assoc == NULL)
return 0;
return a->mode;
}
static struct attribute_group intf_assoc_attr_grp = {
.attrs = intf_assoc_attrs,
.is_visible = intf_assoc_attrs_are_visible,
};
const struct attribute_group *usb_interface_groups[] = {
&intf_attr_grp,
&intf_assoc_attr_grp,
NULL
};
void usb_create_sysfs_intf_files(struct usb_interface *intf)
{
struct usb_device *udev = interface_to_usbdev(intf);
struct usb_host_interface *alt = intf->cur_altsetting;
if (intf->sysfs_files_created || intf->unregistering)
return;
if (!alt->string && !(udev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
alt->string = usb_cache_string(udev, alt->desc.iInterface);
if (alt->string && device_create_file(&intf->dev, &dev_attr_interface))
; /* We don't actually care if the function fails. */
intf->sysfs_files_created = 1;
}
void usb_remove_sysfs_intf_files(struct usb_interface *intf)
{
if (!intf->sysfs_files_created)
return;
device_remove_file(&intf->dev, &dev_attr_interface);
intf->sysfs_files_created = 0;
}