From f07be0b40ae3cbb2ae809d5f4151782f68eabb42 Mon Sep 17 00:00:00 2001 From: "hans@localhost.localdomain" Date: Sun, 3 Aug 2008 11:42:57 +0200 Subject: libv4l: make xawtv happy From: Hans de Goede Be more relaxed in our checks for mixing read and mmap access, we were being more strict in this then certain kernel drivers (bttv) making xawtv unhappy Signed-off-by: Hans de Goede --- v4l2-apps/lib/libv4l/libv4l2/libv4l2-priv.h | 3 - v4l2-apps/lib/libv4l/libv4l2/libv4l2.c | 237 +++++++++++++++------------- v4l2-apps/lib/libv4l/libv4l2/log.c | 8 + 3 files changed, 138 insertions(+), 110 deletions(-) (limited to 'v4l2-apps/lib/libv4l/libv4l2') diff --git a/v4l2-apps/lib/libv4l/libv4l2/libv4l2-priv.h b/v4l2-apps/lib/libv4l/libv4l2/libv4l2-priv.h index d9e73b612..8724832e1 100644 --- a/v4l2-apps/lib/libv4l/libv4l2/libv4l2-priv.h +++ b/v4l2-apps/lib/libv4l/libv4l2/libv4l2-priv.h @@ -68,8 +68,6 @@ #define MIN(a,b) (((a)<(b))?(a):(b)) -enum v4l2_io { v4l2_io_none, v4l2_io_read, v4l2_io_mmap }; - struct v4l2_dev_info { int fd; int flags; @@ -81,7 +79,6 @@ struct v4l2_dev_info { pthread_mutex_t stream_lock; unsigned int no_frames; unsigned int nreadbuffers; - enum v4l2_io io; struct v4lconvert_data *convert; unsigned char *convert_mmap_buf; /* Frame bookkeeping is only done when in read or mmap-conversion mode */ diff --git a/v4l2-apps/lib/libv4l/libv4l2/libv4l2.c b/v4l2-apps/lib/libv4l/libv4l2/libv4l2.c index a16e4801d..2a0dd4837 100644 --- a/v4l2-apps/lib/libv4l/libv4l2/libv4l2.c +++ b/v4l2-apps/lib/libv4l/libv4l2/libv4l2.c @@ -72,7 +72,9 @@ /* Note these flags are stored together with the flags passed to v4l2_fd_open() in v4l2_dev_info's flags member, so care should be taken that the do not use the same bits! */ -#define V4L2_STREAMON 0x0100 +#define V4L2_STREAMON 0x0100 +#define V4L2_BUFFERS_REQUESTED_BY_READ 0x0200 +#define V4L2_STREAM_CONTROLLED_BY_READ 0x0400 #define V4L2_MMAP_OFFSET_MAGIC 0xABCDEF00u @@ -89,52 +91,46 @@ static int v4l2_request_read_buffers(int index) int result; struct v4l2_requestbuffers req; - /* No-op if already done */ - if (devices[index].no_frames) - return 0; - - /* Request buffers */ - req.count = devices[index].nreadbuffers; + /* Note we re-request the buffers if they are already requested as the format + and thus the needed buffersize may have changed. */ + req.count = (devices[index].no_frames)? devices[index].no_frames: + devices[index].nreadbuffers; req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; req.memory = V4L2_MEMORY_MMAP; if ((result = syscall(SYS_ioctl, devices[index].fd, VIDIOC_REQBUFS, &req)) < 0){ int saved_err = errno; - V4L2_LOG_ERR("requesting buffers: %s\n", strerror(errno)); + V4L2_LOG_ERR("requesting %u buffers: %s\n", req.count, strerror(errno)); errno = saved_err; return result; } + if (!devices[index].no_frames && req.count) + devices[index].flags |= V4L2_BUFFERS_REQUESTED_BY_READ; + devices[index].no_frames = MIN(req.count, V4L2_MAX_NO_FRAMES); return 0; } -static int v4l2_unrequest_read_buffers(int index) +static void v4l2_unrequest_read_buffers(int index) { int result; struct v4l2_requestbuffers req; - /* No-op of already done */ - if (devices[index].no_frames == 0) - return 0; + if (!(devices[index].flags & V4L2_BUFFERS_REQUESTED_BY_READ) || + devices[index].no_frames == 0) + return; - /* (Un)Request buffers */ + /* (Un)Request buffers, note not all driver support this, and those + who do not support it don't need it. */ req.count = 0; req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; req.memory = V4L2_MEMORY_MMAP; - if ((result = syscall(SYS_ioctl, devices[index].fd, VIDIOC_REQBUFS, &req)) < 0) { - int saved_err = errno; - V4L2_LOG_ERR("unrequesting buffers: %s\n", strerror(errno)); - errno = saved_err; - return result; - } + if(syscall(SYS_ioctl, devices[index].fd, VIDIOC_REQBUFS, &req) < 0) + return; devices[index].no_frames = MIN(req.count, V4L2_MAX_NO_FRAMES); - if (devices[index].no_frames) { - V4L2_LOG_ERR("number of buffers > 0 after requesting 0 buffers\n"); - errno = EBUSY; - return -1; - } - return 0; + if (devices[index].no_frames == 0) + devices[index].flags &= ~V4L2_BUFFERS_REQUESTED_BY_READ; } static int v4l2_map_buffers(int index) @@ -159,7 +155,7 @@ static int v4l2_map_buffers(int index) } devices[index].frame_pointers[i] = (void *)syscall(SYS_mmap2, NULL, - (size_t)buf.length, PROT_READ, MAP_SHARED, devices[index].fd, + (size_t)buf.length, PROT_READ|PROT_WRITE, MAP_SHARED, devices[index].fd, (__off_t)(buf.m.offset >> MMAP2_PAGE_SHIFT)); if (devices[index].frame_pointers[i] == MAP_FAILED) { int saved_err = errno; @@ -241,6 +237,7 @@ static int v4l2_queue_read_buffer(int index, int buffer_index) if (devices[index].frame_queued & (1 << buffer_index)) return 0; + memset(&buf, 0, sizeof(buf)); buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; buf.memory = V4L2_MEMORY_MMAP; buf.index = buffer_index; @@ -310,6 +307,8 @@ static int v4l2_activate_read_stream(int index) if ((result = v4l2_queue_read_buffers(index))) return result; + devices[index].flags |= V4L2_STREAM_CONTROLLED_BY_READ; + return result = v4l2_streamon(index); } @@ -324,12 +323,48 @@ static int v4l2_deactivate_read_stream(int index) v4l2_unmap_buffers(index); - if ((result = v4l2_unrequest_read_buffers(index))) - return result; + v4l2_unrequest_read_buffers(index); + + devices[index].flags &= ~V4L2_STREAM_CONTROLLED_BY_READ; return 0; } +static int v4l2_buffers_mapped(int index) +{ + unsigned int i; + + if (devices[index].src_fmt.fmt.pix.pixelformat == + devices[index].dest_fmt.fmt.pix.pixelformat) { + /* Normal (no conversion) mode */ + struct v4l2_buffer buf; + + for (i = 0; i < devices[index].no_frames; i++) { + buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; + buf.memory = V4L2_MEMORY_MMAP; + buf.index = i; + if (syscall(SYS_ioctl, devices[index].fd, VIDIOC_QUERYBUF, &buf)) { + int saved_err = errno; + V4L2_LOG_ERR("querying buffer %u: %s\n", i, strerror(errno)); + errno = saved_err; + break; + } + if (buf.flags & V4L2_BUF_FLAG_MAPPED) + break; + } + } else { + /* Conversion mode */ + for (i = 0; i < devices[index].no_frames; i++) + if (devices[index].frame_map_count[i]) + break; + } + + if (i != devices[index].no_frames) + V4L2_LOG("v4l2_buffers_mapped(): buffers still mapped\n"); + + return i != devices[index].no_frames; +} + int v4l2_open (const char *file, int oflag, ...) { @@ -430,7 +465,6 @@ int v4l2_fd_open(int fd, int v4l2_flags) devices[index].no_frames = 0; devices[index].nreadbuffers = V4L2_DEFAULT_NREADBUFFERS; - devices[index].io = v4l2_io_none; devices[index].convert = convert; devices[index].convert_mmap_buf = MAP_FAILED; for (i = 0; i < V4L2_MAX_NO_FRAMES; i++) { @@ -469,7 +503,7 @@ static int v4l2_get_index(int fd) int v4l2_close(int fd) { - int index, result, i; + int index, result; if ((index = v4l2_get_index(fd)) == -1) return syscall(SYS_close, fd); @@ -488,12 +522,8 @@ int v4l2_close(int fd) v4l2_unmap_buffers(index); v4lconvert_destroy(devices[index].convert); if (devices[index].convert_mmap_buf != MAP_FAILED) { - for (i = 0; i < V4L2_MAX_NO_FRAMES; i++) - if (devices[index].frame_map_count[i]) - break; - - if (i != V4L2_MAX_NO_FRAMES) - V4L2_LOG("v4l2 mmap buffers still mapped on close()\n"); + if (v4l2_buffers_mapped(index)) + V4L2_LOG_WARN("v4l2 mmap buffers still mapped on close()\n"); else syscall(SYS_munmap, devices[index].convert_mmap_buf, devices[index].no_frames * V4L2_FRAME_BUF_SIZE); @@ -528,6 +558,34 @@ int v4l2_dup(int fd) return fd; } +static int v4l2_check_buffer_change_ok(int index) +{ + v4l2_unmap_buffers(index); + + /* Check if the app itself still is using the stream */ + if (v4l2_buffers_mapped(index) || + (!(devices[index].flags & V4L2_STREAM_CONTROLLED_BY_READ) && + ((devices[index].flags & V4L2_STREAMON) || + devices[index].frame_queued))) { + V4L2_LOG("v4l2_check_buffer_change_ok(): stream busy\n"); + errno = EBUSY; + return -1; + } + + /* We may change from convert to non conversion mode and + v4l2_unrequest_read_buffers may change the no_frames, so free the + convert mmap buffer */ + syscall(SYS_munmap, devices[index].convert_mmap_buf, + devices[index].no_frames * V4L2_FRAME_BUF_SIZE); + devices[index].convert_mmap_buf = MAP_FAILED; + + if (devices[index].flags & V4L2_STREAM_CONTROLLED_BY_READ) { + V4L2_LOG("deactivating read-stream for settings change\n"); + return v4l2_deactivate_read_stream(index); + } + + return 0; +} int v4l2_ioctl (int fd, unsigned long int request, ...) { @@ -636,17 +694,6 @@ int v4l2_ioctl (int fd, unsigned long int request, ...) break; } - /* Don't allow changing the format when mmap-ed IO is active, we could - allow this to happen in certain special circumstances, but it is - best to consistently deny this so that application developers do not - go expect this to work, because in their test setup it happens to - work. This also keeps the code much saner. */ - if (devices[index].io == v4l2_io_mmap) { - errno = EBUSY; - result = -1; - break; - } - if (devices[index].flags & V4L2_DISABLE_CONVERSION) { result = syscall(SYS_ioctl, devices[index].fd, VIDIOC_TRY_FMT, dest_fmt); @@ -667,16 +714,8 @@ int v4l2_ioctl (int fd, unsigned long int request, ...) break; } - if (devices[index].io == v4l2_io_read) { - V4L2_LOG("deactivating read-stream for format change\n"); - if ((result = v4l2_deactivate_read_stream(index))) { - /* Undo what we've done to leave things in a consisten state */ - if (v4l2_activate_read_stream(index)) - V4L2_LOG_ERR( - "reactivating stream after deactivate failure (AAIIEEEE)\n"); - break; - } - } + if ((result = v4l2_check_buffer_change_ok(index))) + break; result = syscall(SYS_ioctl, devices[index].fd, VIDIOC_S_FMT, &src_fmt); if (result) { @@ -707,26 +746,6 @@ int v4l2_ioctl (int fd, unsigned long int request, ...) int i; struct v4l2_requestbuffers *req = arg; - /* Don't allow mixing read / mmap io, either we control the buffers - (read based io), or the app does */ - if (devices[index].io == v4l2_io_read) { - V4L2_LOG_ERR("to change from read io to mmap io open and close the device first!\n"); - errno = EBUSY; - result = -1; - break; - } - - /* Are any of our fake (convert_mmap_buf) buffers still mapped ? */ - for (i = 0; i < V4L2_MAX_NO_FRAMES; i++) - if (devices[index].frame_map_count[i]) - break; - - if (i != V4L2_MAX_NO_FRAMES) { - errno = EBUSY; - result = -1; - break; - } - /* IMPROVEME (maybe?) add support for userptr's? */ if (req->memory != V4L2_MEMORY_MMAP) { errno = EINVAL; @@ -734,30 +753,20 @@ int v4l2_ioctl (int fd, unsigned long int request, ...) break; } + if ((result = v4l2_check_buffer_change_ok(index))) + break; + /* No more buffers then we can manage please */ if (req->count > V4L2_MAX_NO_FRAMES) req->count = V4L2_MAX_NO_FRAMES; - /* Stop stream and unmap our real mapping of the buffers - (only relevant when we're converting, otherwise a no-op) */ - v4l2_streamoff(index); - v4l2_unmap_buffers(index); - result = syscall(SYS_ioctl, devices[index].fd, VIDIOC_REQBUFS, req); if (result < 0) break; result = 0; /* some drivers return the number of buffers on success */ - /* If we got more frames then we can handle lie to the app */ - if (req->count > V4L2_MAX_NO_FRAMES) - req->count = V4L2_MAX_NO_FRAMES; - - /* Force reallocation of convert_mmap_buf to fit the new no_frames */ - syscall(SYS_munmap, devices[index].convert_mmap_buf, - devices[index].no_frames * V4L2_FRAME_BUF_SIZE); - devices[index].convert_mmap_buf = MAP_FAILED; - devices[index].no_frames = req->count; - devices[index].io = req->count? v4l2_io_mmap:v4l2_io_none; + devices[index].no_frames = MIN(req->count, V4L2_MAX_NO_FRAMES); + devices[index].flags &= ~V4L2_BUFFERS_REQUESTED_BY_READ; } break; @@ -765,6 +774,10 @@ int v4l2_ioctl (int fd, unsigned long int request, ...) { struct v4l2_buffer *buf = arg; + if (devices[index].flags & V4L2_STREAM_CONTROLLED_BY_READ) + if ((result = v4l2_deactivate_read_stream(index))) + break; + /* Do a real query even when converting to let the driver fill in things like buf->field */ result = syscall(SYS_ioctl, devices[index].fd, VIDIOC_QUERYBUF, buf); @@ -781,6 +794,10 @@ int v4l2_ioctl (int fd, unsigned long int request, ...) break; case VIDIOC_QBUF: + if (devices[index].flags & V4L2_STREAM_CONTROLLED_BY_READ) + if ((result = v4l2_deactivate_read_stream(index))) + break; + result = syscall(SYS_ioctl, devices[index].fd, VIDIOC_QBUF, arg); break; @@ -788,6 +805,10 @@ int v4l2_ioctl (int fd, unsigned long int request, ...) { struct v4l2_buffer *buf = arg; + if (devices[index].flags & V4L2_STREAM_CONTROLLED_BY_READ) + if ((result = v4l2_deactivate_read_stream(index))) + break; + result = syscall(SYS_ioctl, devices[index].fd, VIDIOC_DQBUF, buf); if (result) { V4L2_LOG_ERR("dequeing buffer: %s\n", strerror(errno)); @@ -849,11 +870,9 @@ int v4l2_ioctl (int fd, unsigned long int request, ...) case VIDIOC_STREAMON: case VIDIOC_STREAMOFF: - if (devices[index].io != v4l2_io_mmap) { - errno = EINVAL; - result = -1; - break; - } + if (devices[index].flags & V4L2_STREAM_CONTROLLED_BY_READ) + if ((result = v4l2_deactivate_read_stream(index))) + break; if (request == VIDIOC_STREAMON) result = v4l2_streamon(index); @@ -886,22 +905,27 @@ ssize_t v4l2_read (int fd, void* buffer, size_t n) pthread_mutex_lock(&devices[index].stream_lock); - if (devices[index].io == v4l2_io_mmap) { - V4L2_LOG_ERR("to change from mmap io to read io first do request_buffers with a count of 0\n"); - errno = EBUSY; - result = -1; - goto leave; + if (!(devices[index].flags & V4L2_STREAM_CONTROLLED_BY_READ)) { + if ((devices[index].flags & V4L2_STREAMON) || + devices[index].frame_queued) { + errno = EBUSY; + result = -1; + goto leave; + } + if ((result = v4l2_activate_read_stream(index))) + goto leave; } - devices[index].io = v4l2_io_read; - - if ((result = v4l2_activate_read_stream(index))) - goto leave; if ((frame_index = v4l2_dequeue_read_buffer(index, &bytesused)) < 0) { result = -1; goto leave; } + /* ensure buffers are mapped before using them (they could have been + unmapped by a s_fmt ioctl) */ + if ((result = v4l2_map_buffers(index))) + goto leave; + result = v4lconvert_convert(devices[index].convert, &devices[index].src_fmt, &devices[index].dest_fmt, devices[index].frame_pointers[frame_index], bytesused, @@ -948,7 +972,6 @@ void *v4l2_mmap(void *start, size_t length, int prot, int flags, int fd, buffer_index = offset & 0xff; if (buffer_index >= devices[index].no_frames || - devices[index].io != v4l2_io_mmap || /* Got magic offset and not converting ?? */ devices[index].src_fmt.fmt.pix.pixelformat == devices[index].dest_fmt.fmt.pix.pixelformat) { diff --git a/v4l2-apps/lib/libv4l/libv4l2/log.c b/v4l2-apps/lib/libv4l/libv4l2/log.c index 42051ea46..05f6c46d7 100644 --- a/v4l2-apps/lib/libv4l/libv4l2/log.c +++ b/v4l2-apps/lib/libv4l/libv4l2/log.c @@ -131,6 +131,14 @@ void v4l2_log_ioctl(unsigned long int request, void *arg, int result) } } break; + case VIDIOC_REQBUFS: + { + struct v4l2_requestbuffers *req = arg; + + fprintf(v4l2_log_file, " count: %u type: %d memory: %d\n", + req->count, req->type, req->memory); + } + break; } fprintf(v4l2_log_file, "result == %d\n", result); -- cgit v1.2.3