> > On Fri, Aug 30, 2019 at 05:58:39PM +0000, Safford, David (GE Global Research, US) wrote: > > > Thank you for your advice. We also discussed earlier and concluded that > > > checking and raw remapping are enough to work around this. The link is > > > here, https://lkml.org/lkml/2019/8/29/962 . > > > > I don't see Matthew Garrett's agreement on that thread. > > No one has agreed on anything. > > /Jarkko Jarkko, you gave me good advice related to the NVS area and mapping like below. "A function that gets region and then checks if NVS driver has matching one and returns true/false based on that should be good enough. Then you raw ioremap() in the TPM driver." So, I made a patch on your advice and test it. According to my test result, command and response buffers were saved and restored while hibernation. And, there was no side-effect because they were just buffers and hibernation didn't affect the control area of TPM CRB driver. So, I think that saving and restoring buffers during sleep is no problem. I also think your advice and solution are clear and good to work around AMD's fTPM. I will attach my detailed test result soon. Jarkko, I have a question. Do you think this patch is not enough to handle AMD's fTPM problem? If so, would you tell me about it? I will change my patch. Seunghun
