USE the adv7441.
when input HDMI to PORT A, maybe one source of the video(1080 P60) input is ok,but another source of the video(1080 P60) not ,
so when input unsuccessful, read the register, is that
TMDS_PORT_A_ACTIVE，VIDEO_PLL_LOCKED，TMDS_CLK_A_RAW lock ok,
and sometimes V_LOCKED_RAW VERT_FILTER_LOCKED locked unfair.
but in the datasheet,the unfair register is read only.
so I want to know the reason of it?
what‘s the factor with the register V_LOCKED_RAW VERT_FILTER_LOCKED ?