Bug 1409098

Summary: Enabling AMD IOMMU blocks function of Via VL805 USB 3.0 chipset
Product: [Fedora] Fedora Reporter: bob <redzilla.coralnut>
Component: kernelAssignee: Kernel Maintainer List <kernel-maint>
Status: CLOSED INSUFFICIENT_DATA QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: urgent Docs Contact:
Priority: unspecified    
Version: 24CC: cz172638, gansalmon, ichavero, itamar, jonathan, kernel-maint, madhu.chinakonda, mchehab
Target Milestone: ---Flags: jforbes: needinfo?
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Hardware: x86_64   
OS: Linux   
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Last Closed: 2017-04-28 17:09:27 UTC Type: Bug
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output of dmesg and lspci commands none

Description bob 2016-12-29 13:37:12 UTC 
Created attachment 1235877 [details]
output of dmesg and lspci commands

Description of problem:

This is an AMD specific problem.

When IOMMU is enabled in BIOS and Linux version 4.8.15-200.fc24.x86_64 is booted on an AMD 970 chipset, the recognition of the VIA VL805 chipset for USB 3.0 is prevented.  The USB 3.0 ports on the motherboard provided by the VL 805 chipset are non-functional but the USB 2.0 ports provided by the AMD 970 southbridge work fine.

The reported problem is an AMD-Vi IO_PAGE_FAULT:

[   1.718740] AMD-Vi: Event logged [IO_PAGE_FAULT device=02:00.0 domain=0x000f address=0x00000000bea0c6c0 flags=0x0000]

Device 02:00.0 is the VIA USB 3.0 controller:

02:00.0 USB controller: VIA Technologies, Inc. VL805 USB 3.0 Host Controller (rev 01)

It is clear that if IOMMU is enabled, the page faults prevent the VL805 chipset from working.  When IOMMU is disabled in BIOS the VL805 chipset is properly recognized and the USB 3.0 ports are functional.

I have been reporting this problem since F21 but you lame-ass kernel nerds have been ignoring it.  Obviously, you just don't give a hoot about AMD IOMMU, because it's different from the Intel implementation and you're too lazy to work on it.

This problem is not unique to Fedora.  Since I started reporting it back on F21 it has also been reported on Ubuntu and Mint.  The only solution is to disable IOMMU to gain USB 3.0 functionality.

Version-Release number of selected component (if applicable):

Pick a kernel, any kernel.  Not one kernel has ever worked.  Not even the current one:

[    0.000000] Linux version 4.8.15-200.fc24.x86_64 (mockbuild.fedoraproject.org) (gcc version 6.2.1 20160916 (Red Hat 6.2.1-2) (GCC) ) #1 SMP Thu Dec 15 23:09:22 UTC 2016


Version-Release number of selected component (if applicable):

[    0.000000] Linux version 4.8.15-200.fc24.x86_64 (mockbuild.fedoraproject.org) (gcc version 6.2.1 20160916 (Red Hat 6.2.1-2) (GCC) ) #1 SMP Thu Dec 15 23:09:22 UTC 2016


How reproducible:

Are you kidding?

Steps to Reproduce:
1. Toggle status of IOMMU between on/off in BIOS
2. Boot Kernel 4.7.2-201.fc24.x86_64
3. VIA VL803 chipset and USB 3.0 ports are dead if IOMMU enabled.

Additional info:

CPU = AMD FX-8350
Motherboard = Gigabyte GA-970A-UD3P
Chipset = AMD 970

This bug was never addressed when filed for F21 bug 1188654 through F24 bug 1376455.
Comment 1 bob 2017-01-01 18:17:04 UTC 
Additional information gained by additional testing:

1. AMD IOMMU and VL805 USB 3.0 chipset WORK FINE UNDER WINDOWS 7.  It's only under Linux that the hardware fails to work.

2. VL805 USB 3.0 chipset works fine under Linux *IF AND ONLY IF* AMD IOMMU is DISABLED.

3.  VL805 USB 3.0 chipset DOES NOT WORK work under linux IF AMD IOMMU is ENABLED.

4. Problem (3) has been confirmed by other users on other (Debian-based) linux distributions.  These reports do not involve the same _motherboard_ that I am using, but they do involve the same _CHIPSETS_.

5.  These observations suggest that it's a kernel problem, not a hardware problem.  I don't understand how it can be otherwise.
Comment 2 Justin M. Forbes 2017-04-11 14:39:33 UTC 
*********** MASS BUG UPDATE **************

We apologize for the inconvenience.  There are a large number of bugs to go through and several of them have gone stale.  Due to this, we are doing a mass bug update across all of the Fedora 24 kernel bugs.

Fedora 25 has now been rebased to 4.10.9-100.fc24.  Please test this kernel update (or newer) and let us know if you issue has been resolved or if it is still present with the newer kernel.

If you have moved on to Fedora 26, and are still experiencing this issue, please change the version to Fedora 26.

If you experience different issues, please open a new bug report for those.
Comment 3 Justin M. Forbes 2017-04-28 17:09:27 UTC 
*********** MASS BUG UPDATE **************
This bug is being closed with INSUFFICIENT_DATA as there has not been a response in 2 weeks. If you are still experiencing this issue, please reopen and attach the 
relevant data from the latest kernel you are running and any data that might have been requested previously.