[Adding Fenghua Yu to the thread as he submitted the iommu suspend/resume patch (https://lists.linux-foundation.org/pipermail/iommu/2009-March/001247.html) which pertains to this issue] Thought I would clarify that resume from S3 would have never worked with intel_iommu enabled on HP 6930p as opposed to this being a regression for the following reasons - 1) Before the above mentioned patch, when intel_iommu is enabled, during S3/resume we would encounter a kernel crash due to lack of iommu suspend/resume support. 2) After iommu suspend/resume support was added, resume failed on HP 6930p due to enable translation unit code added by the above patch to the iommu resume code path. Thanks, Kamala > -----Original Message----- > From: linux-acpi-owner@xxxxxxxxxxxxxxx [mailto:linux-acpi- > owner@xxxxxxxxxxxxxxx] On Behalf Of Kamala Narasimhan > Sent: Wednesday, September 09, 2009 9:53 PM > To: 'linux-acpi@xxxxxxxxxxxxxxx' > Subject: Resume from sleep fails on HP 6930p with the latest Linux > kernel when iommu is enabled > > I encounter an issue with resume from S3 failing on HP 6930p with the > latest Linux kernel when iommu is enabled. Is this a known issue? > Does anyone have any advice on how to fix/further investigate this > problem? > > Points to note: > > 1) This issue is reproducible only with the latest Linux kernel and > a regression from older ones. > 2) iommu should be enabled through kernel build config or > intel_iommu=on kernel command line. > 3) Happens only on HP 6930p. > 4) Appears to be related to enable translation unit code in the > iommu resume code path. > > How to reproduce the problem? > > 1) Fetch latest Linux kernel. > 2) Build with CONFIG_DMAR_DEFAULT_ON or enable iommu through kernel > command line intel_iommu=on. > 3) Enter S3 after booting with the newly built kernel on HP 6930p. > 4) Attempt to resume from S3 and that should fail. > > Let me know if you need further information to help with this issue. > > Thanks, > Kamala > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" > in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
