Re: [Bug 42679] New: DMA Read on Marvell 88SE9128 fails when Intel's IOMMU is on

[Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>]

(switched to email.  Please respond via emailed reply-to-all, not via the
bugzilla web interface).

On Sat, 28 Jan 2012 17:55:38 GMT
bugzilla-daemon-590EEB7GvNiWaY/ihj7yzEB+6BGkLq7r@public.gmane.org wrote:

> https://bugzilla.kernel.org/show_bug.cgi?id=42679

I don't know if this is a SATA issue or intel-iommu.  Could you guys
please take a look?

>            Summary: DMA Read on Marvell 88SE9128 fails when Intel's IOMMU
>                     is on
>            Product: Memory Management
>            Version: 2.5
>           Platform: All
>         OS/Version: Linux
>               Tree: Mainline
>             Status: NEW
>           Severity: normal
>           Priority: P1
>          Component: Other
>         AssignedTo: akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org
>         ReportedBy: pawel.zaq-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org
>         Regression: No
> 
> 
> Created an attachment (id=72217)
>  --> (https://bugzilla.kernel.org/attachment.cgi?id=72217)
> Output of `dmesg' command
> 
> I have a MSI Z68A-GD80 B3 motherboard and when I try to enable Intel's IOMMU
> (kernel booted with intel_iommu=on), integrated Marvell 88SE9128 SATA
> controller doesn't work.
> 
> To reproduce:
> 1. Compile and prepare kernel with Intel IOMMU support enabled
> (CONFIG_INTEL_IOMMU=y).
> 2. Reboot the computer.
> 3. Enter BIOS and enable VT-d.
> 4. Boot the kernel with intel_iommu=on parameter.
> 
> Right after boot, kernel reports the following errors (SATA controller is at
> 0b:00.0):
> 
> [    2.639774] DRHD: handling fault status reg 3
> [    2.639782] DMAR:[DMA Read] Request device [0b:00.1] fault addr fff00000 
> [    2.639783] DMAR:[fault reason 02] Present bit in context entry is clear
> 
> After a while these entries appear:
> 
> [    7.625837] ata14.00: qc timeout (cmd 0xa1)
> [    7.628341] ata14.00: failed to IDENTIFY (I/O error, err_mask=0x4)
> [    7.935483] ata14: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
> [   17.908407] ata14.00: qc timeout (cmd 0xa1)
> [   17.910935] ata14.00: failed to IDENTIFY (I/O error, err_mask=0x4)
> [   17.912276] ata14: limiting SATA link speed to 1.5 Gbps
> [   18.219077] ata14: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
> [   48.134607] ata14.00: qc timeout (cmd 0xa1)
> [   48.137508] ata14.00: failed to IDENTIFY (I/O error, err_mask=0x4)
> [   48.444646] ata14: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
> 
> When there is a disk connected to the controller it does not work. When there
> are none, computer starts normally, apart from the huge lag caused by,
> presumably, probing the device.
> 
> Since this is the secondary controller on these motherboards, to eliminate
> those symptoms you can just plug disk in one of available ports of the built-in
> Intel SATA controller and disable Marvell's one using BIOS. The other
> work-around, if you need to use eSATA capabilities of the latter, is to disable
> VT-d techonology also using BIOS.