> > 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". I agree with your idea. It seems to make trouble. So, I would like to do like your idea below. > 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 This solution is great and clear to me. I will make a new patch on your advice and test it in my machine. After that, I will send it again soon. I really appreciate it. Seunghun
