Disable PCI devices via systemd

[Raman Gupta]

I have an Intel motherboard sound card, and twoHDMI audio sound cards
provided by each of my ATI video cards:

# lspci | grep -i audio
00:1b.0 Audio device: Intel Corporation Patsburg High Definition Audio
Controller (rev 05)
01:00.1 Audio device: ATI Technologies Inc Device aaa0
02:00.1 Audio device: ATI Technologies Inc Device aaa0

I don't have anything plugged into the ATI HDMI ports so I want to
disable those devices, as I get annoying error messages in KDE at
startup time and periodically in /var/log/messages. For example:

[   13.018758] ALSA sound/pci/hda/hda_eld.c:334 HDMI: ELD buf size is
0, force 128
[   13.018772] ALSA sound/pci/hda/hda_eld.c:351 HDMI: invalid ELD data
byte 0

I cannot blacklist the module, because the "snd_hda_intel" module that
drives the Intel sound card on my motherboardalso recognizes the ATI
cards, according to lspci-v.

The following solution does workperfectly:

# echo 1 > /sys/devices/pci0000:00/0000:00:02.0/0000:01:00.1/remove
# echo 1 > /sys/devices/pci0000:00/0000:00:03.0/0000:02:00.1/remove

In the old days, the above two lines would go into rc.local. What is
the systemd way to not create those devices? Or is there an alternate
approach to turn off the HDMI sound cards on the ATI cards?

Regards,
Raman