On Fri, Sep 28, 2012 at 05:18:18PM -0600, Shuah Khan wrote: > > +void amd_iommu_disable(void) > > +{ > > + amd_iommu_suspend(); > > Is it safe to attempt to suspend when iommu is in suspend state? In > other words what happens if amd_iommu_disable() gets called when iommu > is already in suspend state?
Yes, this is safe. It just trns a bit to 0 which is already 0. >> > +int amd_iommu_reenable(int mode) > > +{ > > + amd_iommu_resume(); > > Same question as above. Safe to do a resume, when in resumed state? Safe too, it just writes values to the hardware which are already there. This was also proven by testing. Joerg -- AMD Operating System Research Center Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach General Managers: Alberto Bozzo Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/