imx6q ov5640_mipi ERROR: v4l2 capture: VIDIOC_QBUF: buffer already queued

[richarddestiny]

Hi,all

      ov5640   i2c  is ok, and i can see the  clock and data wave, i want to get a  picture with  v4l2 ,and have  this  problem, why?

Thanks for your help.

Have a great day,

[carlsherratt]

Just so everyone knows, This for me was a hardware issue. some of the physical lines on the board to the camera connector were not connected, now connected and fully working.

[carlsherratt]

Hi Richard,

I have the same output i.e

cat /dev/video0

ERROR: v4l2 capture: mxc_v4l_read timeout counter 0

imx-ipuv3 2400000.ipu: Not a CSI channel

Could you explain what you mean by "i have solved the problem，it’s the camera work wrong" as it may help myself and others? Thankyou.

[sindhujakapugan]

Hi Richard,

I have the  output i.e

cat /dev/video0

cat /dev/video0  > test.mpg

ov540 mode detected

master writing

master writing

master writing

master writing

master writing

master writing

master writing

master writing

master writing

master writing

master writing

master writing

ERROR: v4l2 capture: mxc_v4l_read timeout counter 0

cat: /dev/video0: Timer expired

could you explain how to solve this problem

Thankyou.

[richarddestiny · Accepted solution]

Hi,all

     thanks for all of your help,i have solved the problem，it’s the camera work wrong~~

[jimmychan]

what BSP are you using?

please double check the id number of csi and ipu setting. which csi and ipu are you using?

[richarddestiny]

Hi，jimmy chan

     the  kernel is  v3.10.17   ，

the  device tree：

&mipi_csi {

  status = "okay";

  ipu_id = <0>;

  csi_id = <1>;

  v_channel = <0>;

  lanes = <2>;

};

v4l2_cap_1 {

  compatible = "fsl,imx6q-v4l2-capture";

  ipu_id = <0>;

  csi_id = <1>;

  mclk_source = <0>;

  status = "okay";

  };

&i2c2 {

  clock-frequency = <100000>;

  pinctrl-names = "default";

  pinctrl-0 = <&pinctrl_i2c2_2>;

  status = "okay";

.................

  ov5640_mipi: ov5640_mipi@3c { /* i2c2 driver */

  compatible = "ovti,ov5640_mipi";

  reg = <0x3c>;

  clocks = <&clks 201>;

  clock-names = "csi_mclk";

  DOVDD-supply = <&vgen4_reg>; /* 1.8v */

  AVDD-supply = <&vgen3_reg>;  /* 2.8v, rev C board is VGEN3

  rev B board is VGEN5 */

  DVDD-supply = <&vgen2_reg>;  /* 1.5v*/

  pwn-gpios = <&gpio1 19 1>;   /* active low: SD1_CLK */

  rst-gpios = <&gpio1 20 0>;   /* active high: SD1_DAT2 */

  csi_id = <1>;

  mclk = <24000000>;

  mclk_source = <0>;

  };

....................

so,it's  right?

Thanks for your help.

Have a great day,

[jimmychan]

for csi_id=1, the v_channel should be 1.

[richarddestiny]

ov5640_set_virtual_channel(ov5640_data.csi);

yes,it's  1

[jimmychan]

what board are you using?

if not the sabresd, are you using the same gpio pins for rst and pwdn?

[richarddestiny]

it;s  imx6q   sabresd    kernel:3.10.17  rst  and pwdn  didn't  controled by gpio

thanks！

[angelo_d]

From what i remember you should be able to capture single frames as i mentioned, maybe the video0 / 1 are output devices. Do you have some other videoXX, like video16 or the like ?

[richarddestiny]

HI，angelo dureghello

     root@imx6qdlsolo:~# ls /dev/video*

     /dev/video0   /dev/video16  /dev/video18  /dev/video20

     /dev/video1   /dev/video17  /dev/video19

     root@imx6qdlsolo:~# cat /dev/video16

     cat: read error: Invalid argument

     root@imx6qdlsolo:~# cat /dev/video17

     cat: read error: Invalid argument

     root@imx6qdlsolo:~#

Thanks for your help.

Have a great day,

[angelo_d]

what happen capturing single frames (still) ? Should be able to capture 1 frame with

cat /dev/video0 > test.mpg

[richarddestiny]

Hi,angelo dureghello

root@imx6qdlsolo:~# cat /dev/video1   > test.mpg

ERROR: v4l2 capture: mxc_v4l_read timeout counter 0

imx-ipuv3 2400000.ipu: Not a CSI channel

cat: read error: Timer expired

Thanks for your help.

Have a great day,