Revision 2bbd00aef0671bfe3c2ca5ba67097246257de125 authored by Johannes Weiner on 26 February 2021, 01:16:47 UTC, committed by Linus Torvalds on 26 February 2021, 17:41:00 UTC
On NOHZ, the periodic vmstat flushers on each CPU can go to sleep and
won't wake up until stat changes are detected in the per-cpu deltas of the
zone vmstat counters.

In commit 75ef71840539 ("mm, vmstat: add infrastructure for per-node
vmstats") per-node counters were introduced, and subsequently most stats
were moved from the zone to the node level.  However, the node counters
weren't added to the NOHZ wakeup detection.

In theory this can cause per-cpu errors to remain in the user-reported
stats indefinitely.  In practice this only affects a handful of sub
counters (file_mapped, dirty and writeback e.g.) because other page state
changes at the node level likely involve a change at the zone level as
well (alloc and free, lru ops).  Also, nobody has complained.

Fix it up for completeness: wake up vmstat refreshing on node changes.
Also remove the BUILD_BUG_ONs that assert counter size; we haven't relied
on it since we added sizeof() to the range calculation in commit
13c9aaf7fa01 ("mm/vmstat.c: fix NUMA statistics updates").

Link: https://lkml.kernel.org/r/20210202184342.118513-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent a052d4d
Raw File
hid-samsung.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  HID driver for some samsung "special" devices
 *
 *  Copyright (c) 1999 Andreas Gal
 *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
 *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
 *  Copyright (c) 2006-2007 Jiri Kosina
 *  Copyright (c) 2008 Jiri Slaby
 *  Copyright (c) 2010 Don Prince <dhprince.devel@yahoo.co.uk>
 *
 *  This driver supports several HID devices:
 *
 *  [0419:0001] Samsung IrDA remote controller (reports as Cypress USB Mouse).
 *	various hid report fixups for different variants.
 *
 *  [0419:0600] Creative Desktop Wireless 6000 keyboard/mouse combo
 *	several key mappings used from the consumer usage page
 *	deviate from the USB HUT 1.12 standard.
 */

/*
 */

#include <linux/device.h>
#include <linux/usb.h>
#include <linux/hid.h>
#include <linux/module.h>

#include "hid-ids.h"

/*
 * There are several variants for 0419:0001:
 *
 * 1. 184 byte report descriptor
 * Vendor specific report #4 has a size of 48 bit,
 * and therefore is not accepted when inspecting the descriptors.
 * As a workaround we reinterpret the report as:
 *   Variable type, count 6, size 8 bit, log. maximum 255
 * The burden to reconstruct the data is moved into user space.
 *
 * 2. 203 byte report descriptor
 * Report #4 has an array field with logical range 0..18 instead of 1..15.
 *
 * 3. 135 byte report descriptor
 * Report #4 has an array field with logical range 0..17 instead of 1..14.
 *
 * 4. 171 byte report descriptor
 * Report #3 has an array field with logical range 0..1 instead of 1..3.
 */
static inline void samsung_irda_dev_trace(struct hid_device *hdev,
		unsigned int rsize)
{
	hid_info(hdev, "fixing up Samsung IrDA %d byte report descriptor\n",
		 rsize);
}

static __u8 *samsung_irda_report_fixup(struct hid_device *hdev, __u8 *rdesc,
		unsigned int *rsize)
{
	if (*rsize == 184 && rdesc[175] == 0x25 && rdesc[176] == 0x40 &&
			rdesc[177] == 0x75 && rdesc[178] == 0x30 &&
			rdesc[179] == 0x95 && rdesc[180] == 0x01 &&
			rdesc[182] == 0x40) {
		samsung_irda_dev_trace(hdev, 184);
		rdesc[176] = 0xff;
		rdesc[178] = 0x08;
		rdesc[180] = 0x06;
		rdesc[182] = 0x42;
	} else
	if (*rsize == 203 && rdesc[192] == 0x15 && rdesc[193] == 0x0 &&
			rdesc[194] == 0x25 && rdesc[195] == 0x12) {
		samsung_irda_dev_trace(hdev, 203);
		rdesc[193] = 0x1;
		rdesc[195] = 0xf;
	} else
	if (*rsize == 135 && rdesc[124] == 0x15 && rdesc[125] == 0x0 &&
			rdesc[126] == 0x25 && rdesc[127] == 0x11) {
		samsung_irda_dev_trace(hdev, 135);
		rdesc[125] = 0x1;
		rdesc[127] = 0xe;
	} else
	if (*rsize == 171 && rdesc[160] == 0x15 && rdesc[161] == 0x0 &&
			rdesc[162] == 0x25 && rdesc[163] == 0x01) {
		samsung_irda_dev_trace(hdev, 171);
		rdesc[161] = 0x1;
		rdesc[163] = 0x3;
	}
	return rdesc;
}

#define samsung_kbd_mouse_map_key_clear(c) \
	hid_map_usage_clear(hi, usage, bit, max, EV_KEY, (c))

static int samsung_kbd_mouse_input_mapping(struct hid_device *hdev,
	struct hid_input *hi, struct hid_field *field, struct hid_usage *usage,
	unsigned long **bit, int *max)
{
	struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
	unsigned short ifnum = intf->cur_altsetting->desc.bInterfaceNumber;

	if (1 != ifnum || HID_UP_CONSUMER != (usage->hid & HID_USAGE_PAGE))
		return 0;

	dbg_hid("samsung wireless keyboard/mouse input mapping event [0x%x]\n",
		usage->hid & HID_USAGE);

	switch (usage->hid & HID_USAGE) {
	/* report 2 */
	case 0x183: samsung_kbd_mouse_map_key_clear(KEY_MEDIA); break;
	case 0x195: samsung_kbd_mouse_map_key_clear(KEY_EMAIL);	break;
	case 0x196: samsung_kbd_mouse_map_key_clear(KEY_CALC); break;
	case 0x197: samsung_kbd_mouse_map_key_clear(KEY_COMPUTER); break;
	case 0x22b: samsung_kbd_mouse_map_key_clear(KEY_SEARCH); break;
	case 0x22c: samsung_kbd_mouse_map_key_clear(KEY_WWW); break;
	case 0x22d: samsung_kbd_mouse_map_key_clear(KEY_BACK); break;
	case 0x22e: samsung_kbd_mouse_map_key_clear(KEY_FORWARD); break;
	case 0x22f: samsung_kbd_mouse_map_key_clear(KEY_FAVORITES); break;
	case 0x230: samsung_kbd_mouse_map_key_clear(KEY_REFRESH); break;
	case 0x231: samsung_kbd_mouse_map_key_clear(KEY_STOP); break;
	default:
		return 0;
	}

	return 1;
}

static __u8 *samsung_report_fixup(struct hid_device *hdev, __u8 *rdesc,
	unsigned int *rsize)
{
	if (USB_DEVICE_ID_SAMSUNG_IR_REMOTE == hdev->product)
		rdesc = samsung_irda_report_fixup(hdev, rdesc, rsize);
	return rdesc;
}

static int samsung_input_mapping(struct hid_device *hdev, struct hid_input *hi,
	struct hid_field *field, struct hid_usage *usage,
	unsigned long **bit, int *max)
{
	int ret = 0;

	if (USB_DEVICE_ID_SAMSUNG_WIRELESS_KBD_MOUSE == hdev->product)
		ret = samsung_kbd_mouse_input_mapping(hdev,
			hi, field, usage, bit, max);

	return ret;
}

static int samsung_probe(struct hid_device *hdev,
		const struct hid_device_id *id)
{
	int ret;
	unsigned int cmask = HID_CONNECT_DEFAULT;

	ret = hid_parse(hdev);
	if (ret) {
		hid_err(hdev, "parse failed\n");
		goto err_free;
	}

	if (USB_DEVICE_ID_SAMSUNG_IR_REMOTE == hdev->product) {
		if (hdev->rsize == 184) {
			/* disable hidinput, force hiddev */
			cmask = (cmask & ~HID_CONNECT_HIDINPUT) |
				HID_CONNECT_HIDDEV_FORCE;
		}
	}

	ret = hid_hw_start(hdev, cmask);
	if (ret) {
		hid_err(hdev, "hw start failed\n");
		goto err_free;
	}

	return 0;
err_free:
	return ret;
}

static const struct hid_device_id samsung_devices[] = {
	{ HID_USB_DEVICE(USB_VENDOR_ID_SAMSUNG, USB_DEVICE_ID_SAMSUNG_IR_REMOTE) },
	{ HID_USB_DEVICE(USB_VENDOR_ID_SAMSUNG, USB_DEVICE_ID_SAMSUNG_WIRELESS_KBD_MOUSE) },
	{ }
};
MODULE_DEVICE_TABLE(hid, samsung_devices);

static struct hid_driver samsung_driver = {
	.name = "samsung",
	.id_table = samsung_devices,
	.report_fixup = samsung_report_fixup,
	.input_mapping = samsung_input_mapping,
	.probe = samsung_probe,
};
module_hid_driver(samsung_driver);

MODULE_LICENSE("GPL");
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