{"id":1798,"date":"2022-07-20T18:14:49","date_gmt":"2022-07-20T17:14:49","guid":{"rendered":"https:\/\/pmortensen.eu\/world2\/?p=1798"},"modified":"2025-07-17T23:21:50","modified_gmt":"2025-07-17T22:21:50","slug":"enabling-both-usb-3-and-usb-2-ports-for-a-ga-970a-ds3p-motherboard","status":"publish","type":"post","link":"https:\/\/pmortensen.eu\/world2\/2022\/07\/20\/enabling-both-usb-3-and-usb-2-ports-for-a-ga-970a-ds3p-motherboard\/","title":{"rendered":"Enabling both USB 3 and USB 2 ports for the ‘Gigabyte’ GA-970A-DS3P motherboard"},"content":{"rendered":"

The short version: With default BIOS<\/a> settings (which enable USB 3 ports) for the Gigabyte<\/a> GA-970A-DS3P<\/a> motherboard<\/a>, the USB 2 ports do not work (at least in Linux), only the two external USB 3 ports. In Linux, the GRUB configuration parameter “GRUB_CMDLINE_LINUX” must contain “iommu=soft” to get the USB 2 ports and USB 3 ports to work at the same time.<\/p>\n

This blog post is essentially the seminal 2013 forum post “GA-970A-DS3P revision 1 no USB 3.0<\/a>“, but this provides one data point that the solution with “iommu=soft” actually works (and is required) for a particular BIOS version<\/em><\/strong> and works (and is required) for a particular version of a particular Linux distribution of vintage 2020<\/em><\/strong>. For instance, later versions of a Linux distribution, say Ubuntu<\/a> (or later updates to a particular version), may break the solution. And hopefully this blog post has clearer instructions with some additional checks to be confident in the solution.<\/p>\n

It also shows that even in 2022, with the mainstream Ubuntu 22.04<\/a>, the Linux community has still not solved the problem. This is ridiculous.<\/p>\n

(Note: The motherboard is not to be confused with GA-970A-D3P (without “S”) which, for instance, has screen display output connectors (for HDMI<\/a>, etc.), but fewer USB ports)<\/p>\n

Introduction<\/h2>\n

With default settings in the BIOS and in Linux, the USB 2 ports on the GA-970A-DS3P motherboard do not work out of the box<\/em>. With a USB hub on one of the USB 3 ports, the system nominally works fine, but there are six direct USB ports that can not be used (e.g., for keyboards and mice). For instance, this prevents using the workaround of using a USB 2 port instead of a USB 3 port for making macro keys on a QMK keyboard function properly<\/a>.<\/p>\n

It has nothing<\/em> to do with the BIOS version<\/h2>\n

The motherboard used to test this on already had the latest version (FD<\/em>, released 2016-05-02).<\/p>\n

It has nothing<\/em> to do with hardware<\/h2>\n

E.g., broken hardware. Some Internet searches will return such suggestions. Changing the BIOS setting \u201cIOMMU\u201d in menu \u201cPeripherals\u201d to “Enabled” will enable the USB 2 ports, and they work just fine (but the USB 3 ports will not work then). Thus this problem has nothing to do with broken hardware.<\/p>\n

Internet searches<\/h2>\n

It is not easy to come up with search terms that will not result in near 100% false positives, even using the very specific name of the motherboard (GA-970A-D3P). However, these search terms in combination turned out to be very effective:<\/p>\n

\r\nIOMMU enable USB 2 ports\r\n<\/pre>\n
<\/p>\n
Linux version<\/h2>\n
Both distribution and kernel version.<\/p>\n
Identifying the kernel version<\/h3>\n
In a terminal, on a Ubuntu\/Debian<\/a> derived system: <\/p>\n
\r\ncat \/proc\/version_signature\r\n<\/pre>\n
Alternatively, this may be more widely applicable, not just for Ubuntu:<\/p>\n
\r\nhostnamectl\r\n<\/pre>\n
It also outputs the name of Linux distribution and its version.<\/p>\n
Identifying the distribution, incl. version<\/h3>\n
In a terminal, on a Ubuntu\/Debian derived system: <\/p>\n
\r\nlsb_release -a\r\n<\/pre>\n
On Fedora:<\/p>\n
\r\ncat \/etc\/fedora-release\r\n<\/pre>\n
Results<\/h3>\n
These systems were found to exhibit the problem and the fix described here worked:<\/p>\n
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