Re: Failure to shutdown/reboot with intel_iommu=on

[Joerg Roedel]

+ Baolu, Maintainer of Intel IOMMU

Baolu, does that ring any bells?

On Wed, May 06, 2020 at 04:46:02PM +0200, Uwe Kleine-König wrote:
> Hello,
> 
> On my Lenovo T460p I cannot shutdown and reboot when the iommu is
> enabled. This is using linux 5.2.7 as provided by Debian, 5.6.4 has the
> same problem. Suspend/resume also fails; I suspect this is the same
> issue.
> 
> When requesting power off the kernel messages just end with:
> 
> 	sd 0:0:0:0: [sda] Synchronizing SCSI cache
> 	sd 0:0:0:0: [sda] Stopping disk
> 	e1000e: EEE TX LPI TIMER: 00000011
> 	ACPI: Preparing to enter system sleep state S5
> 	reboot: Power down
> 	acpi_power_off called
> 
> (photo at https://www.kleine-koenig.org/tmp/uklsiommu.jpg in case I
> mistyped something. Full dmesg and lspci -vvv at
> https://www.kleine-koenig.org/tmp/uklsiommu.tar.gz with and without
> iommu enabled.)
> 
> With the iommu disabled (CONFIG_INTEL_IOMMU_DEFAULT_ON unset or
> intel_iommu=off on cmdline) the machine just works as expected
> (including working suspend/resume).
> 
> I already talked to tglx on irc but unfortunately no new insights
> resulted from that.
> 
> Any ideas how to fix or continue debugging the issue?
> 
> Best regards
> Uwe