[U-Boot] [PATCH 5/6] sunxi: video: Give hotplug-detect (hpd) signal some time to show up

[Hans de Goede]

Hi,

On 24-12-14 03:25, B.R. Oake wrote:
> On 20/12/14 14:42, Hans de Goede wrote:
>> When using a hdmi powered hdmi to vga dongle, and cold booting a sunxi
>> device, the hpd detect code would not see the dongle (until a warm reboot),
>> because the dongle needs some time to boot.
>>
>> Testing has shown that this dongle needs 213ms to respond on a cold boot,
>> so wait up to 300ms for a hpd signal to show up before giving up.
>
> Hi Hans,
>
> I'm using a similar convertor but it sometimes takes longer to be ready,
> depending on what screen is connected.  With an old VGA monitor, I've seen
> it take up to 1230ms before returning the HPD signal, presumably while it
> collects information from the monitor.
>
> Would it be acceptable to increase the wait from 300ms to about 1500ms?

That means delaying the boot by another 1.2 seconds on all machines which
have hdmi without a cable plugged in. I'm not sure I'm a fan of that.

Ian, what is your take on this ?

Regards,

Hans