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authorSergey Korolev <s.korolev@ndmsystems.com>2020-08-09 19:12:30 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-10-02 15:32:46 +0200
commit97b65223c18f131e18d662448381b727c04c2325 (patch)
tree80c5e0b99f0e817b76722436dc4f2941afb145ec /drivers/usb
parentda0cb6310094c1b6113aa8d8d860b9b45d6da437 (diff)
USB: core: remove polling for /sys/kernel/debug/usb/devices
The latest reference to usbfs_conn_disc_event() removed in commit fb28d58b72aa ("USB: remove CONFIG_USB_DEVICEFS") in 2012 and now a user poll() waits infinitely for content changes. Signed-off-by: Sergey Korolev <s.korolev@ndmsystems.com> Link: https://lore.kernel.org/r/20200809161233.13135-1-s.korolev@ndmsystems.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/core/devices.c41
-rw-r--r--drivers/usb/core/usb.h1
2 files changed, 0 insertions, 42 deletions
diff --git a/drivers/usb/core/devices.c b/drivers/usb/core/devices.c
index 696b2b692b83..1ef2de6e375a 100644
--- a/drivers/usb/core/devices.c
+++ b/drivers/usb/core/devices.c
@@ -39,7 +39,6 @@
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/gfp.h>
-#include <linux/poll.h>
#include <linux/usb.h>
#include <linux/usbdevice_fs.h>
#include <linux/usb/hcd.h>
@@ -97,22 +96,6 @@ static const char format_endpt[] =
/* E: Ad=xx(s) Atr=xx(ssss) MxPS=dddd Ivl=D?s */
"E: Ad=%02x(%c) Atr=%02x(%-4s) MxPS=%4d Ivl=%d%cs\n";
-/*
- * Wait for an connect/disconnect event to happen. We initialize
- * the event counter with an odd number, and each event will increment
- * the event counter by two, so it will always _stay_ odd. That means
- * that it will never be zero, so "event 0" will never match a current
- * event, and thus 'poll' will always trigger as readable for the first
- * time it gets called.
- */
-static struct device_connect_event {
- atomic_t count;
- wait_queue_head_t wait;
-} device_event = {
- .count = ATOMIC_INIT(1),
- .wait = __WAIT_QUEUE_HEAD_INITIALIZER(device_event.wait)
-};
-
struct class_info {
int class;
char *class_name;
@@ -146,12 +129,6 @@ static const struct class_info clas_info[] = {
/*****************************************************************/
-void usbfs_conn_disc_event(void)
-{
- atomic_add(2, &device_event.count);
- wake_up(&device_event.wait);
-}
-
static const char *class_decode(const int class)
{
int ix;
@@ -623,25 +600,7 @@ static ssize_t usb_device_read(struct file *file, char __user *buf,
return total_written;
}
-/* Kernel lock for "lastev" protection */
-static __poll_t usb_device_poll(struct file *file,
- struct poll_table_struct *wait)
-{
- unsigned int event_count;
-
- poll_wait(file, &device_event.wait, wait);
-
- event_count = atomic_read(&device_event.count);
- if (file->f_version != event_count) {
- file->f_version = event_count;
- return EPOLLIN | EPOLLRDNORM;
- }
-
- return 0;
-}
-
const struct file_operations usbfs_devices_fops = {
.llseek = no_seek_end_llseek,
.read = usb_device_read,
- .poll = usb_device_poll,
};
diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
index 98e7d1ee63dc..c893f54a3420 100644
--- a/drivers/usb/core/usb.h
+++ b/drivers/usb/core/usb.h
@@ -191,7 +191,6 @@ extern const struct attribute_group *usb_interface_groups[];
extern struct usb_driver usbfs_driver;
extern const struct file_operations usbfs_devices_fops;
extern const struct file_operations usbdev_file_operations;
-extern void usbfs_conn_disc_event(void);
extern int usb_devio_init(void);
extern void usb_devio_cleanup(void);