diff options
Diffstat (limited to 'drivers/media/v4l2-core')
| -rw-r--r-- | drivers/media/v4l2-core/videobuf2-core.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index 2075bac748c0..3f0cdb150dfd 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -6,6 +6,9 @@ * Author: Pawel Osciak <pawel@osciak.com> * Marek Szyprowski <m.szyprowski@samsung.com> * + * The vb2_thread implementation was based on code from videobuf-dvb.c: + * (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs] + * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation. @@ -18,6 +21,8 @@ #include <linux/poll.h> #include <linux/slab.h> #include <linux/sched.h> +#include <linux/freezer.h> +#include <linux/kthread.h> #include <media/v4l2-dev.h> #include <media/v4l2-fh.h> @@ -3005,6 +3010,147 @@ size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count, } EXPORT_SYMBOL_GPL(vb2_write); +struct vb2_threadio_data { + struct task_struct *thread; + vb2_thread_fnc fnc; + void *priv; + bool stop; +}; + +static int vb2_thread(void *data) +{ + struct vb2_queue *q = data; + struct vb2_threadio_data *threadio = q->threadio; + struct vb2_fileio_data *fileio = q->fileio; + bool set_timestamp = false; + int prequeue = 0; + int index = 0; + int ret = 0; + + if (V4L2_TYPE_IS_OUTPUT(q->type)) { + prequeue = q->num_buffers; + set_timestamp = + (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) == + V4L2_BUF_FLAG_TIMESTAMP_COPY; + } + + set_freezable(); + + for (;;) { + struct vb2_buffer *vb; + + /* + * Call vb2_dqbuf to get buffer back. + */ + memset(&fileio->b, 0, sizeof(fileio->b)); + fileio->b.type = q->type; + fileio->b.memory = q->memory; + if (prequeue) { + fileio->b.index = index++; + prequeue--; + } else { + call_void_qop(q, wait_finish, q); + ret = vb2_internal_dqbuf(q, &fileio->b, 0); + call_void_qop(q, wait_prepare, q); + dprintk(5, "file io: vb2_dqbuf result: %d\n", ret); + } + if (threadio->stop) + break; + if (ret) + break; + try_to_freeze(); + + vb = q->bufs[fileio->b.index]; + if (!(fileio->b.flags & V4L2_BUF_FLAG_ERROR)) + ret = threadio->fnc(vb, threadio->priv); + if (ret) + break; + call_void_qop(q, wait_finish, q); + if (set_timestamp) + v4l2_get_timestamp(&fileio->b.timestamp); + ret = vb2_internal_qbuf(q, &fileio->b); + call_void_qop(q, wait_prepare, q); + if (ret) + break; + } + + /* Hmm, linux becomes *very* unhappy without this ... */ + while (!kthread_should_stop()) { + set_current_state(TASK_INTERRUPTIBLE); + schedule(); + } + return 0; +} + +/* + * This function should not be used for anything else but the videobuf2-dvb + * support. If you think you have another good use-case for this, then please + * contact the linux-media mailinglist first. + */ +int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv, + const char *thread_name) +{ + struct vb2_threadio_data *threadio; + int ret = 0; + + if (q->threadio) + return -EBUSY; + if (vb2_is_busy(q)) + return -EBUSY; + if (WARN_ON(q->fileio)) + return -EBUSY; + + threadio = kzalloc(sizeof(*threadio), GFP_KERNEL); + if (threadio == NULL) + return -ENOMEM; + threadio->fnc = fnc; + threadio->priv = priv; + + ret = __vb2_init_fileio(q, !V4L2_TYPE_IS_OUTPUT(q->type)); + dprintk(3, "file io: vb2_init_fileio result: %d\n", ret); + if (ret) + goto nomem; + q->threadio = threadio; + threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name); + if (IS_ERR(threadio->thread)) { + ret = PTR_ERR(threadio->thread); + threadio->thread = NULL; + goto nothread; + } + return 0; + +nothread: + __vb2_cleanup_fileio(q); +nomem: + kfree(threadio); + return ret; +} +EXPORT_SYMBOL_GPL(vb2_thread_start); + +int vb2_thread_stop(struct vb2_queue *q) +{ + struct vb2_threadio_data *threadio = q->threadio; + struct vb2_fileio_data *fileio = q->fileio; + int err; + + if (threadio == NULL) + return 0; + call_void_qop(q, wait_finish, q); + threadio->stop = true; + vb2_internal_streamoff(q, q->type); + call_void_qop(q, wait_prepare, q); + q->fileio = NULL; + fileio->req.count = 0; + vb2_reqbufs(q, &fileio->req); + kfree(fileio); + err = kthread_stop(threadio->thread); + threadio->thread = NULL; + kfree(threadio); + q->fileio = NULL; + q->threadio = NULL; + return err; +} +EXPORT_SYMBOL_GPL(vb2_thread_stop); /* * The following functions are not part of the vb2 core API, but are helper |