1 files changed, 80 insertions, 0 deletions
diff --git a/debian/patches/debian/hid-avoid-abi-change-in-4.17.6.patch b/debian/patches/debian/hid-avoid-abi-change-in-4.17.6.patch
new file mode 100644
index 000000000000..050bdf2b4451
--- /dev/null
+++ b/debian/patches/debian/hid-avoid-abi-change-in-4.17.6.patch
@@ -0,0 +1,80 @@
+From: Ben Hutchings <ben@decadent.org.uk>
+Date: Thu, 12 Jul 2018 00:39:38 +0100
+Subject: HID: Avoid ABI change in 4.17.6
+Forwarded: not-needed
+
+Commit 8f732850df1b "HID: core: allow concurrent registration of
+drivers" introduced atomic bit-operations on hid_device::status, and
+changed its type from unsigned int to unsigned long as required for
+those operations.
+
+Revert the type change and use cmpxchg() for the bit-operations,
+since it supports unsigned int.
+
+---
+--- a/drivers/hid/hid-core.c
++++ b/drivers/hid/hid-core.c
+@@ -1929,6 +1929,34 @@ static int hid_bus_match(struct device *
+ 	return hid_match_device(hdev, hdrv) != NULL;
+ }
+ 
++static void clear_status_flag(unsigned int flag, unsigned int *status)
++{
++	unsigned int expect, old;
++
++	expect = READ_ONCE(*status);
++	for (;;) {
++		old = cmpxchg(status, expect, expect & ~flag);
++		if (old == expect)
++			break;
++		expect = old;
++	}
++}
++
++static bool test_and_set_status_flag(unsigned int flag, unsigned int *status)
++{
++	unsigned int expect, old;
++
++	expect = READ_ONCE(*status);
++	for (;;) {
++		old = cmpxchg(status, expect, expect | flag);
++		if (old == expect)
++			break;
++		expect = old;
++	}
++
++	return old & flag;
++}
++
+ static int hid_device_probe(struct device *dev)
+ {
+ 	struct hid_driver *hdrv = to_hid_driver(dev->driver);
+@@ -1942,7 +1970,7 @@ static int hid_device_probe(struct devic
+ 	}
+ 	hdev->io_started = false;
+ 
+-	clear_bit(ffs(HID_STAT_REPROBED), &hdev->status);
++	clear_status_flag(HID_STAT_REPROBED, &hdev->status);
+ 
+ 	if (!hdev->driver) {
+ 		id = hid_match_device(hdev, hdrv);
+@@ -2208,7 +2236,7 @@ static int __hid_bus_reprobe_drivers(str
+ 
+ 	if (hdev->driver == hdrv &&
+ 	    !hdrv->match(hdev, hid_ignore_special_drivers) &&
+-	    !test_and_set_bit(ffs(HID_STAT_REPROBED), &hdev->status))
++	    !test_and_set_status_flag(HID_STAT_REPROBED, &hdev->status))
+ 		return device_reprobe(dev);
+ 
+ 	return 0;
+--- a/include/linux/hid.h
++++ b/include/linux/hid.h
+@@ -569,7 +569,7 @@ struct hid_device {							/* device repo
+ 	bool battery_avoid_query;
+ #endif
+ 
+-	unsigned long status;						/* see STAT flags above */
++	unsigned int status;						/* see STAT flags above */
+ 	unsigned claimed;						/* Claimed by hidinput, hiddev? */
+ 	unsigned quirks;						/* Various quirks the device can pull on us */
+ 	bool io_started;						/* If IO has started */