On 06 Mar, Jim Lesurf <jcgl@xxxxxxxxxxxxxxx> wrote:
I'm using an HDMI switch (Monoprice) to let me use my monitor with both
my ARMX6 and a Linux box. In general this works fine and the switch has
an optical spdif output that lets me get good digital audio from the
ARMX6.
To use the Linux box I set the switch to connect it to the monitor and
leave the ARMX6 unpowered.
To use the ARMX6 I set the switch to connect it to the monitor and leave
the linux box unpowered.
At this point the more alert readers will realise that what comes next is
a "however..." :-)
However I get a problem when I want to change from using the Linux
machine to the ARMX6. I shut down the Linux machine, then switch the HDMI
to connect the ARMX6, then turn on the power to the ARMX6. It then boots
up as normal *except* that I get an error once the desktop has appeared.
This is in a system error box with "Error" in its window title bar and
the text.
EDID checksum is incorrect (block 1 of 1 failed) - cannot read monitor
settings.
(Sometimes it says block 0 or 0.)
The screen display then works OK when I clear the error, and I can use
the system in general terms. It has reverted to the monitor definition
file I was using before the HDMI ability to read EDID was added. All
works fine *except* using HDMI for *audio*.
Trying to issue another ReadEDID fails with the error. It is then
impossible to get the HDMI to take audio - presumably because the lack of
having read the screen's settings means the system can't tell if it can
take *any* audio at all.
Has anyone else encountered this problem?
I can then shut down everything and wait a while. Starting up again with
the system switched to use the ARMX6 from the start works as it should
with no such audio problem *provided* I wait quite a long time.
It isn't enough to wait until the leds on the ARMX6 and screen have gone
dark. The indicator LED on the monitor flashes for a minute or more after
power has been switched off (at the mains). Waiting until this stops
isn't long enough to clear the above behaviour. I have to wait rather
longer.
I'm not sure which part of the system takes this long to forget the
problem but it can be a pest to have to wait this long. Fortunately, I
can generally take this into account beforehand and avoid needing to get
the problem when it matters. But I'm wondering why it is happening and
how it might be fixed.
I *suspect* it might be the HDMI switch - although it draws a lot of
power from its PSU (gets noticably hot in use) so I'm surprised if it can
'remember' this for so long. Its LEDs die as soon as I turn off power at
the mains. But I've not had any other HDMI switches to compare with the
one I'm using. So again, I'm curious to know if others have been using a
switch without the problem.
Jim
