i.MX ProcessorsのトピックImx7 ov5640 request buffer problem

Imx7 ov5640 request buffer problem

Ananth — Thu, 28 Sep 2017 13:48:14 GMT

Hi All,

I am using imx7 saber board ov5640_mipi.c driver.

I have a problem in using the camera driver available at drivers/media/platform/mxc/subdev/ in linux-4.1.15 kernel.

On 1st time, i was able to get buffer from mxc_v4l2_capture.c (available in imx-test-5.7). But when i looped the following code in mxc_v4l2_capture application, i end up in REQ_BUF Failure from the driver.

    while (1) {
       fd_v4l = v4l_capture_setup();
       v4l_capture_test(fd_v4l, argv[argc-1]);
   }
On debugging found that VIDIOC_REQBUFS ioctl __buffers_in_use(q) more than 1 (2 active users).

On commenting drivers/media/v4l2-core/videobuf2-core.c __reqbufs function, i was able to run mxc_v4l2_capture.out multiple times with out error

#if 0
       if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) {
           mutex_unlock(&q->mmap_lock);
           dprintk(1, "memory in use, cannot free\n");
           printk("%s %s %d\n", __FILE__, __func__, __LINE__);
           return -EBUSY;
       }
#endif

My Queries

1. buf->refcount is 2, when the buffers are trying to free at drivers/media/v4l2-core/videobuf2-dma-contig.c vb2_dc_put function and the complete freeing only done at vb2_queue_release drivers/media/v4l2-core/videobuf2-core.c called at the end of application execution. How come refcount becomes 2 (Please refer patch and logs) ?

2. Is there any other stable branch for imx7 saber board camera driver ?

Thanks and regards,

Ananth.

Original Attachment has been moved to: Modification_debug.patch.zip

Original Attachment has been moved to: default_working_log.txt.zip

Re: Imx7 ov5640 request buffer problem

art — Fri, 29 Sep 2017 09:17:00 GMT

Seems that you have to clearly release the buffer after executing v4l_capture_test. Please try it.

Have a great day,
Artur

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Re: Imx7 ov5640 request buffer problem

Ananth — Sat, 30 Sep 2017 04:41:26 GMT

Hi Artur,

Do we have any sample application which runs on imx7 with repeatedly doing Streamoff and streamon for camera driver ?

Thanks and regards,

Ananth.

Re: Imx7 ov5640 request buffer problem

Ananth — Wed, 04 Oct 2017 04:53:22 GMT

The problem is the buffers are not freed property from driver.

After stream off is performed the buffers should be freed.

1. With reqbuf ioctl send count =0.

2. mmaped buffers should be freed using munmap API.

Regards,

Ananth