> -----Original Message----- > From: iommu <[email protected]> On Behalf Of Koba Ko > Sent: Sunday, June 14, 2020 10:47 PM > To: David Woodhouse; Lu Baolu; Joerg Roedel > Cc: [email protected]; Kai Heng Feng; Linux Kernel Mailing > List > Subject: [Issue]platform/x86: iommu: System can't shutdown because iommu > driver keeps checking the status of DMA_GSTS_TES > > hi All, > I have a machine and there's only intel gpu. > the secureboot and vt-d is enabled in BIOS. > On the Ubuntu desktop, I do s2idle first and restart the machine. > The machine can't restart successfully, so I need to press the power > button to shutdown. > I tried each of the following and the issue can't be triggered. > 1. disable secure boot in BIOS.
Just to explain why this happens, on many of Dell's systems VT-d is only enabled when secure boot is enabled. > 2. intel_iommu=off. > 3. intel_iomm=igfx_off. > 4. nomodeset > 5. i915.modeset=0. > > After I investigate further, find inte_iommu keeps checking the status > of DMA_GSTS_TES. > During the procedure of restart, the driver would disable iommu translation > and > check the status of DMA_GSTS_TES until status of DMA_GSTS_TES is 0. > > If you need more information, I can provide it. > > Thanks > Koba Ko > _______________________________________________ > iommu mailing list > [email protected] > https://lists.linuxfoundation.org/mailman/listinfo/iommu This is reported on TGL pre-production system, but actually same symptom is also happening in ICL production systems such as XPS 7390 2-in-1 and XPS 9300. Details for the ICL issue are available here: https://bugzilla.kernel.org/show_bug.cgi?id=206571 A user did bisect it back to commit 6c3a44ed3c553c324845744f30bcd1d3b07d61fd in 5.5. Glancing through the code and comparing the suspend case, I would ask is it just a case of missing a flush at shutdown (IE iommu_flush_all)?
