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i.MX6 IPU : When should "ext_vsync" be set in a proper value?

Question asked by Nori Shinozaki on Aug 17, 2016
Latest reply on Sep 26, 2016 by Nori Shinozaki

Hello Champs,

 

I'm looking at BSP 3.14.28_1.0.0 kernel source.

In a source file, mxc_v4l2_capture.c in drivers/media/platform/mxc/capture directory,

 

a function "mxc_v4l_open()" just sets 0 to "ext_vsnyc", but sets proper target values to Vsync_pol, Hsync_pol in line 1661 and 1662 like this.

 

        csi_param.Vsync_pol = ifparm.u.bt656.nobt_vs_inv;

        csi_param.Hsync_pol = ifparm.u.bt656.nobt_hs_inv;

 

On the other hand, "mxc_v4l2_s_param()" explicitly sets proper values for Vsync_pol, Hsync_pol and ext_vsync like this:

 

    csi_param.Vsync_pol = ifparm.u.bt656.nobt_vs_inv;

    csi_param.Hsync_pol = ifparm.u.bt656.nobt_hs_inv;

    csi_param.ext_vsync = ifparm.u.bt656.bt_sync_correct;

 

Is there any reason why "mxc_v4l_open()" doesn't set "ext_vsnyc" like above?

 

I just thought, all parameters should be properly set in "mxc_v4l_open()" without calling "mxc_v4l2_s_param()".

 

BR,

Nori Shinozaki

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