Hello Azhar, On 12/20/2017 04:08 PM, Shaikh, Azhar wrote: [snip] >>> >>>> It seems that on machines with a PS/2 controller connected to the >>>> LPC bus the BIOS is already doing this, so I've a feeling that it >>>> not being done on devices with a TPM is a bug in the firmware >>> >>> Absolutely agree, system integratos should make sure that all the >>> devices connected to the LPC either have CLKRUN protocol support and >>> is enabled or disable the CLKRUN protocol permanently. >> >> As far as I understand it, this is exactly the issue here: They know that there >> are devices that do not support the CLKRUN protocol (the TPM in this case), >> but they still need to enable it to prevent other issues. So for the TPM to >> continue to work, CLKRUN needs to be disabled temporarily while the TPM is >> active. >> > > Yes that was the reason to have this fix. We needed CLKRUN to be enabled for Braswell SOC . But the TPM in this case SLB9655 does not support CLKRUN (please check this public documentation https://www.infineon.com/dgdl/Infineon-TPM+SLB+9665-DS-v10_15-EN.pdf?fileId=5546d4625185e0e201518b83d9273d87 section 2.3 Power Management). So as Alexander mentioned CLKRUN is disabled while TPM transactions are in progress. > Yes I do understand that. Please read my answer to Alexander's email and also my question (and Hans') about keeping the CLKRUN protocol permanently disabled. Best regards, -- Javier Martinez Canillas Software Engineer - Desktop Hardware Enablement Red Hat
