Ubuntu 16.04: Graphics card being detected wrongly, battery getting drained

Question

I use an Inspiron 7548 which ships with an AMD Radeon R7 M270 graphics card. However, Ubuntu is detecting it as an R7 M265.

LSPCI:

00:00.0 Host bridge: Intel Corporation Broadwell-U Host Bridge -OPI (rev 09)
00:02.0 VGA compatible controller: Intel Corporation Broadwell-U Integrated Graphics (rev 09)
00:03.0 Audio device: Intel Corporation Broadwell-U Audio Controller (rev 09)
00:14.0 USB controller: Intel Corporation Wildcat Point-LP USB xHCI Controller (rev 03)
00:16.0 Communication controller: Intel Corporation Wildcat Point-LP MEI Controller #1 (rev 03)
00:1b.0 Audio device: Intel Corporation Wildcat Point-LP High Definition Audio Controller (rev 03)
00:1c.0 PCI bridge: Intel Corporation Wildcat Point-LP PCI Express Root Port #1 (rev e3)
00:1c.3 PCI bridge: Intel Corporation Wildcat Point-LP PCI Express Root Port #4 (rev e3)
00:1c.4 PCI bridge: Intel Corporation Wildcat Point-LP PCI Express Root Port #5 (rev e3)
00:1d.0 USB controller: Intel Corporation Wildcat Point-LP USB EHCI Controller (rev 03)
00:1f.0 ISA bridge: Intel Corporation Wildcat Point-LP LPC Controller (rev 03)
00:1f.2 SATA controller: Intel Corporation Wildcat Point-LP SATA Controller [AHCI Mode] (rev 03)
00:1f.3 SMBus: Intel Corporation Wildcat Point-LP SMBus Controller (rev 03)
07:00.0 Network controller: Intel Corporation Wireless 3160 (rev 83)
08:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Opal XT [Radeon R7 M265]

At this point of time, I need help either to make Ubuntu detect it correctly, or disable the graphics card (I tried to blacklist the radeon module, but it didn't take effect (not even after rebooting twice).

Answer 1

There's no Official AMD drivers/support for AMD cards at this time. Although I'm still unsure as to why it's not being detected. This could cause issues in disabling it if it's not being detected.

Either way, this is how I disabled it on my Ubuntu 16.04;

1) Edit the file /etc/default/grub. Add radeon.runpm=0 to the end of the line with GRUB_CMDLINE_LINUX_DEFAULT after quiet splash.

2) Save the file and run sudo update-grub. And then reboot.

3) After reboot, run a terminal and type in sudo cat /sys/kernel/debug/vgaswitcheroo/switch. This should show you your two cards like so:

0:IGD:+:Pwr:0000:01:05.0 
1:DIS: :Pwr:0000:02:00.1 

IGD is your Intel graphics, DIS is your Discreet graphics(AMD). If you only see ONE card listed here, then you have more issues you need to solve to get the card detected before you can continue with these steps. If you DO see two entries, then carry on.

4) Now type echo DIS > /sys/kernel/debug/vgaswitcheroo/switch

IF and only if you get an error typing the above command, then type these two lines (replace with your own username) and then try step 4 again;

4a) sudo chown yourusername /sys/kernel/debug

4b) sudo chown yourusername /sys/kernel/debug/vgaswitcheroo/switch

4e) EXAMPLE OF ABOVE ONLY sudo chown xtoro /sys/kernel......

If you're unsure of your username, type whoami in terminal.

5) When step 4 is successful and has no errors, type

echo OFF > /sys/kernel/debug/vgaswitcheroo/switch

echo OFF > /sys/kernel/debug/vgaswitcheroo/switch

(Yes you type the same thing twice.)

6) Type in sudo cat /sys/kernel/debug/vgaswitcheroo/switch again, and you should see

0:IGD:+:Pwr:0000:01:05.0 
1:DIS: :Off:0000:02:00.1 

Note that after DIS, you should see "Off' now.

Now edit the file /etc/init.d/rc.local

Before exit 0, add these 2 lines if you had a permission error on step 4:

chown USERNAME /sys/kernel/debug

chown USERNAME /sys/kernel/debug/vgaswitcheroo/switch

This will allow you to disable the card every time

You can also add the following 3 lines between the chown and exit 0 lines to keep it disabled after every boot:

echo DIS > /sys/kernel/debug/vgaswitcheroo/switch

echo OFF > /sys/kernel/debug/vgaswitcheroo/switch

echo OFF > /sys/kernel/debug/vgaswitcheroo/switch

Reboot and then run

sudo cat /sys/kernel/debug/vgaswitcheroo/switch to confirm that your AMD card remains disabled after every reboot.