v4l2loopback: unstable-2022-08-05 -> unstable-2023-02-19

stdenv.mkDerivation rec {

  pname = "v4l2loopback";

  version = "unstable-2022-08-05-${kernel.version}";

  version = "unstable-2023-02-19-${kernel.version}";

  src = fetchFromGitHub {

    owner = "umlaeute";

    repo = "v4l2loopback";

    rev = "76434ab6f71d5ecbff8a218ff6bed91ea2bf73b8";

    sha256 = "sha256-TdZacRkFAO2HAEbljzXeJ241VcDqSwBECq3bnn7yvBY=";

    rev = "fb410fc7af40e972058809a191fae9517b9313af";

    hash = "sha256-gLFtR7s+3LUQ0BZxHbmaArHbufuphbtAX99nxJU3c84=";

  };

  patches = [

    # fix bug https://github.com/umlaeute/v4l2loopback/issues/535

    ./revert-pr518.patch

  ];

  hardeningDisable = [ "format" "pic" ];

  preBuild = ''

diff --git a/v4l2loopback.c b/v4l2loopback.c

index 2ab1f76..2514f09 100644

--- a/v4l2loopback.c

+++ b/v4l2loopback.c

@@ -92,17 +92,6 @@ MODULE_LICENSE("GPL");

 		}                                                      \

 	} while (0)

-/* TODO: Make sure that function is never interrupted. */

-static inline int mod_inc(int *number, int mod)

-{

-	int result;

-	result = (*number + 1) % mod;

-	if (unlikely(result < 0))

-		result += mod;

-	*number = result;

-	return result;

-}

-

 static inline void v4l2l_get_timestamp(struct v4l2_buffer *b)

 {

 	/* ktime_get_ts is considered deprecated, so use ktime_get_ts64 if possible */

@@ -1424,8 +1413,9 @@ static int vidioc_reqbufs(struct file *file, void *fh,

 			i = dev->write_position;

 			list_for_each_entry(pos, &dev->outbufs_list,

 					    list_head) {

-				dev->bufpos2index[mod_inc(&i, b->count)] =

+				dev->bufpos2index[i % b->count] =

 					pos->buffer.index;

+				++i;

 			}

 		}

@@ -1489,9 +1479,10 @@ static void buffer_written(struct v4l2_loopback_device *dev,

 	del_timer_sync(&dev->timeout_timer);

 	spin_lock_bh(&dev->lock);

-	dev->bufpos2index[mod_inc(&dev->write_position, dev->used_buffers)] =

+	dev->bufpos2index[dev->write_position % dev->used_buffers] =

 		buf->buffer.index;

 	list_move_tail(&buf->list_head, &dev->outbufs_list);

+	++dev->write_position;

 	dev->reread_count = 0;

 	check_timers(dev);

@@ -1586,7 +1577,8 @@ static int get_capture_buffer(struct file *file)

 		if (dev->write_position >

 		    opener->read_position + dev->used_buffers)

 			opener->read_position = dev->write_position - 1;

-		pos = mod_inc(&opener->read_position, dev->used_buffers);

+		pos = opener->read_position % dev->used_buffers;

+		++opener->read_position;

 	}

 	timeout_happened = dev->timeout_happened;

 	dev->timeout_happened = 0;