Hot plug detect issue

Hello george,

Please provide more information.  What device are you referring to? 

Thank you,

~Leonard  

Sorry, We use sn65dsi86 and display is Acer CB280HK.

Thanks

Hi,

When the DisplayPort device is removed, if you clear the register 0xF5 with a write of 0xFF and then read back, does register 0xF5 still read back as 0x06?

Thanks
David

Hi David,

When the DP port monitor is removed, I write 0xFF to register 0xF5, the value  of register 0xF5 is 0x00

Then I plugin monitor, the value of register of  0xF5 is 0x02.

I replug the monitor, the value of register 0xF5 is 0x06

Hi,

What you are seeing is the correct behavior.

A HPD_REMOVAL event is defined as a change that causes the HPD state to transition from INSERTION state to the REMOVAL state. A HPD_INSERT event is defined as a change that causes the HPD state to transition from the REMOVAL state to the INSERTION state. The REPLUG event is caused by the sink deasserting HPD for more than 2 ms but less than 100 ms.

So when you plug in the monitor, the register 0x0F5 will be 0x02 indicating the insertion of the cable. When you remove the cable, bit 3 of the register 0xF5 will be set to indicate the removal of the cable. With bit 2 not being cleared, you will read back a 0x06.

The register 0xF5 will not clear itself, you will have to write 0xFF to it to clear it.

Thanks

David