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| author | Sergey Korolev <s.korolev@ndmsystems.com> | 2020-08-09 19:12:30 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-10-02 15:32:46 +0200 |
| commit | 97b65223c18f131e18d662448381b727c04c2325 (patch) | |
| tree | 80c5e0b99f0e817b76722436dc4f2941afb145ec /drivers/usb | |
| parent | da0cb6310094c1b6113aa8d8d860b9b45d6da437 (diff) | |
| download | linux-97b65223c18f131e18d662448381b727c04c2325.tar.bz2 | |
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.c | 41 | ||||
| -rw-r--r-- | drivers/usb/core/usb.h | 1 |
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); |