On Thu, Aug 29, 2019 at 06:34:37PM +0300, Jarkko Sakkinen wrote: > On Wed, Aug 28, 2019 at 06:36:04PM +0900, Seunghun Han wrote: > > > > > > On Wed, Aug 28, 2019 at 01:36:30AM +0900, Seunghun Han wrote: > > > > > > > I got your point. Is there any problem if some regions which don't > > > > need to be handled in NVS area are saved and restored? If there is a > > > > problem, how about adding code for ignoring the regions in NVS area to > > > > the nvs.c file like Jarkko said? If we add the code, we can save and > > > > restore NVS area without driver's interaction. > > > > > > The only thing that knows which regions should be skipped by the NVS > > > driver is the hardware specific driver, so the TPM driver needs to ask > > > the NVS driver to ignore that region and grant control to the TPM > > > driver. > > > > > > -- > > > Matthew Garrett | mjg59@xxxxxxxxxxxxx > > > > Thank you, Matthew and Jarkko. > > It seems that the TPM driver needs to handle the specific case that > > TPM regions are in the NVS. I would make a patch that removes TPM > > regions from the ACPI NVS by requesting to the NVS driver soon. > > > > Jarkko, > > I would like to get some advice on it. What do you think about > > removing TPM regions from the ACPI NVS in TPM CRB driver? If you don't > > mind, I would make the patch about it. > > I'm not sure if ignoring is right call. Then the hibernation behaviour > for TPM regions would break. > > Thus, should be "ask access" rather than "grant control". Or "reserve access" as NVS driver does not have intelligence to do any policy based decision here. 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. /Jarkko
