new/buildroot/package/libv4l/0003-libv4l-add-V4L2_MEMORY_DMABUF-memory-support.patch
2025-05-10 21:58:58 +08:00

94 lines
3.0 KiB
Diff

From 81471d8195f3da907205ec7384bccfe9c8f846fd Mon Sep 17 00:00:00 2001
From: "vicent.chi" <vicent.chi@rock-chips.com>
Date: Thu, 31 Oct 2019 11:46:12 +0800
Subject: [PATCH 3/7] libv4l: add V4L2_MEMORY_DMABUF memory support
Signed-off-by: vicent.chi <vicent.chi@rock-chips.com>
---
lib/libv4l2/libv4l2-priv.h | 1 +
lib/libv4l2/libv4l2.c | 23 +++++++++++++++++++++--
2 files changed, 22 insertions(+), 2 deletions(-)
diff --git a/lib/libv4l2/libv4l2-priv.h b/lib/libv4l2/libv4l2-priv.h
index 1924c91..30dd1bc 100644
--- a/lib/libv4l2/libv4l2-priv.h
+++ b/lib/libv4l2/libv4l2-priv.h
@@ -104,6 +104,7 @@ struct v4l2_dev_info {
void *plugin_library;
void *dev_ops_priv;
const struct libv4l_dev_ops *dev_ops;
+ int has_dmabuf_memory;
};
/* From v4l2-plugin.c */
diff --git a/lib/libv4l2/libv4l2.c b/lib/libv4l2/libv4l2.c
index 0c02bec..0b17888 100644
--- a/lib/libv4l2/libv4l2.c
+++ b/lib/libv4l2/libv4l2.c
@@ -543,7 +543,7 @@ static int v4l2_deactivate_read_stream(int index)
static int v4l2_needs_conversion(int index)
{
- if (devices[index].convert == NULL)
+ if (devices[index].convert == NULL || devices[index].has_dmabuf_memory)
return 0;
return v4lconvert_needs_conversion(devices[index].convert,
@@ -1305,12 +1305,18 @@ no_capture_request:
struct v4l2_requestbuffers *req = arg;
/* IMPROVEME (maybe?) add support for userptr's? */
- if (req->memory != V4L2_MEMORY_MMAP) {
+ if (req->memory != V4L2_MEMORY_MMAP && req->memory != V4L2_MEMORY_DMABUF) {
errno = EINVAL;
result = -1;
break;
}
+ if (req->memory == V4L2_MEMORY_DMABUF) {
+ devices[index].has_dmabuf_memory = 1;
+ V4L2_LOG("memory type is V4L2_MEMORY_DMABUF, "
+ "buf conversion and mmap emulation are disabled\n");
+ }
+
result = v4l2_check_buffer_change_ok(index);
if (result)
break;
@@ -1563,6 +1569,14 @@ ssize_t v4l2_read(int fd, void *dest, size_t n)
goto leave;
}
+ if (!(devices[index].flags & V4L2_USE_READ_FOR_READ) &&
+ devices[index].has_dmabuf_memory) {
+ V4L2_PERROR("memory type is V4L2_MEMORY_DMABUF, "
+ "no support v4l2 read\n");
+ errno = EINVAL;
+ return -1;
+ }
+
/* Since we need to do conversion try to use mmap (streaming) mode under
the hood as that safes a memcpy for each frame read.
@@ -1627,6 +1641,7 @@ void *v4l2_mmap(void *start, size_t length, int prot, int flags, int fd,
void *result;
index = v4l2_get_index(fd);
+
if (index != -1 && devices[index].dev_ops->mmap) {
pthread_mutex_lock(&devices[index].stream_lock);
result = devices[index].dev_ops->mmap(
@@ -1637,6 +1652,10 @@ void *v4l2_mmap(void *start, size_t length, int prot, int flags, int fd,
return result;
}
+ if (index != -1 && devices[index].has_dmabuf_memory) {
+ return (void *)SYS_MMAP(start, length, prot, flags, fd, offset);
+ }
+
if (index == -1 ||
/* Check if the mmap data matches our answer to QUERY_BUF. If it doesn't,
let the kernel handle it (to allow for mmap-based non capture use) */
--
2.20.1