Comment 385 for bug 312756

@VizFdez

I've experimented the same Error with i915 and radeon module loaded together,
and "solved" it by blacklisting radeon module.
add a file en /etc/modprobe.d with a .conf name (ex: custom-blacklist-radeon.conf)
and write into: blacklist radeon
or execute:
echo "blacklist radeon" | sudo tee /etc/modprobe.d/custom-blacklist-radeon.conf

One other issue i've seen with both modules is that the power consumption
is higher, even when turning off the discrete Ati card by means of vgaswitcheroo,
compared to having only i915 loaded and turn the card off by acpi_call module.