Messages in this thread | | | Date | Tue, 17 Jan 2017 13:59:33 -0700 | From | Jason Gunthorpe <> | Subject | Re: [PATCH] tpm/tpm_i2c_infineon: ensure no ongoing commands on shutdown |
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On Tue, Jan 17, 2017 at 12:13:36PM -0800, Andrey Pronin wrote: > > Is there some way we can have the TPM core do this without requiring > > the driver to add a shutdown the struct driver? > > > > Maybe we could put something in chip->dev->driver? Not sure.. > > I can play more with it. We can check in tpm_chip_register() if > chip->dev->driver->shutdown is NULL, and, if so, set it to a default > handler. Or, do register_reboot_notifier() instead, to avoid messing > with struct device_driver from tpm-chip.c. Not sure if that's a > consideration at alli - any reason not to mess with those structures?
I think ordering is important here, the TPM core has to do any shutdown before the driver shutdown method. That restriction might entirely preclude using a reboot_notifier.
> Whatever we do, we should allow the drivers to still send > (vendor-specific) commands from their shutdown handlers.
A vendor specific command should be done via a new core TPM mechanism. I really want to keep access drivers (eg i2c, lpc, spi, etc) out of the buisness of *assuming* they are connected to any specific chip.
So, the core should detect chip XYZ and then issue the required vendor-specific command in some way.
The driver shutdown would be used to close the access interface in some way.
> But, yes, setting a default handler through chip->dev->driver > might just be good enough.
Probably the *best* thing would be to add shutdown to 'struct class' in the driver core like suspend/resume?
Jason
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