Date:	Mon, 28 Mar 2011 16:16:59 -0400
From:	Jeff Layton <jlayton@...chiereds.net>
To:	Sisir Koppaka <sisir.koppaka@...il.com>
Cc:	Stefan Berger <stefanb@...ux.vnet.ibm.com>,
	linux-kernel@...r.kernel.org, tpmdd-devel@...ts.sourceforge.net
Subject: Re: TPM chip prevents machine from suspending

On Tue, 29 Mar 2011 01:27:05 +0530
Sisir Koppaka <sisir.koppaka@...il.com> wrote:

> On Tue, Mar 29, 2011 at 1:15 AM, Jeff Layton <jlayton@...chiereds.net> wrote:
> > On Mon, 28 Mar 2011 14:12:41 -0400
> > Jeff Layton <jlayton@...chiereds.net> wrote:
> >
> >> On Mon, 28 Mar 2011 13:25:06 -0400
> >> Stefan Berger <stefanb@...ux.vnet.ibm.com> wrote:
> >>
> >> > On 03/28/2011 10:08 AM, Jeff Layton wrote:
> >> > > My wife's machine apparently has a TPM chip in it. Since I upgraded it
> >> > > to Fedora 14, it fails to suspend consistently. On the first attempt to
> >> > > suspend it, it works fine. Once it has woken back up however, it will
> >> > > not suspend again. Here's the dmesg log from such an attempt:
> >> > >
> >> > > [  202.460967] PM: Syncing filesystems ... done.
> >> > > [  202.464818] PM: Preparing system for mem sleep
> >> > > [  202.485968] Freezing user space processes ... (elapsed 0.01 seconds) done.
> >> > > [  202.497079] Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done.
> >> > > [  202.508067] PM: Entering mem sleep
> >> > > [  202.508086] Suspending console(s) (use no_console_suspend to debug)
> >> > > [  202.508451] sd 3:0:0:0: [sdb] Synchronizing SCSI cache
> >> > > [  202.508562] sd 2:0:0:0: [sda] Synchronizing SCSI cache
> >> > > [  202.508616] sd 3:0:0:0: [sdb] Stopping disk
> >> > > [  202.511956] parport_pc 00:0b: disabled
> >> > > [  202.512127] serial 00:09: disabled
> >> > > [  202.512134] serial 00:09: wake-up capability disabled by ACPI
> >> > > [  202.536058] legacy_suspend(): pnp_bus_suspend+0x0/0x82 returns 38
> >> > > [  202.536061] PM: Device 00:02 failed to suspend: error 38
> >> > > [  202.997517] sd 2:0:0:0: [sda] Stopping disk
> >> > > [  202.997806] PM: Some devices failed to suspend
> >> > > [  202.998085] sd 2:0:0:0: [sda] Starting disk
> >> > > [  202.998144] sd 3:0:0:0: [sdb] Starting disk
> >> > > [  202.998614] serial 00:09: activated
> >> > > [  202.999158] parport_pc 00:0b: activated
> >> > > [  204.543094] PM: resume of devices complete after 1545.282 msecs
> >> > > [  204.543268] PM: Finishing wakeup.
> >> > > [  204.543270] Restarting tasks ... done.
> >> > >
> >> > > ...error 38 is ENOSYS, and the 00:02 is this:
> >> > >
> >> > > # cat /sys/bus/pnp/devices/00\:02/id
> >> > > IFX0102
> >> > > PNP0c31
> >> > Also the tpm_tis driver handles both of these. Can you confirm which
> >> > module that laptop was using  (tpm_tis or tpm_infineon) and try whether
> >> > one of them works better than the other one? Please do a reboot between
> >> > trying one and then the other.
> >> >
> >>
> >> It's using tpm_tis:
> >>
> >> lrwxrwxrwx. 1 root root 0 Mar 28 13:40 /sys/bus/pnp/devices/00:02/driver -> ../../../bus/pnp/drivers/tpm_tis
> >>
> >> FWIW, the fedora kernels have this:
> >>
> >> CONFIG_TCG_TPM=y
> >> CONFIG_TCG_TIS=y
> >> CONFIG_TCG_NSC=m
> >> CONFIG_TCG_ATMEL=m
> >> CONFIG_TCG_INFINEON=m
> >>
> >> When I boot, tpm_infineon is also plugged in, but I can remove that
> >> module and nothing seems to change (not sure what's plugging it in).
> >>
> >> I can try using tpm_infineon, but I'm not sure how to disable tpm_tis
> >> with it compiled in like this -- is that possible?
> >>
> >> > Try the following before and after a suspend/resume:
> >> >
> >> > cd /sys
> >> > find . | grep caps$ | xargs cat
> >> >
> >> > It should display manufacturer data.
> >> >
> >>
> >> There's only one "caps" file. Here's the before (after a fresh reboot):
> >>
> >> # cat ./devices/pnp0/00:02/caps
> >> Manufacturer: 0x49465800
> >> TCG version: 1.2
> >> Firmware version: 1.0
> >>
> >> ...after a successful suspend/resume cycle:
> >>
> >> # cat ./devices/pnp0/00:02/caps
> >>
> >> ...it gives no output at all. Guess that lends some weight to the
> >> theory of it not being reset properly on resume?
> >>
> >> Thanks for the help so far...
> >
> > FWIW, I turned up dynamic debugging on the tpm files and got this in
> > the ring buffer when I tried to read from "caps":
> >
> > [ 6880.495071] tpm_tis 00:02: A TPM error (38) occurred attempting to determine the manufacturer
> >
> > I don't see any obvious places that return ENOSYS in the tpm code, so
> > I'm not clear on where that's coming from...
> >
> 
> From drivers/char/tpm/tpm.c,
> 
> static ssize_t transmit_cmd(struct tpm_chip *chip, struct tpm_cmd_t *cmd,
>                             int len, const char *desc)
> {
>         int err;
> 
>         len = tpm_transmit(chip,(u8 *) cmd, len);
>         if (len <  0)
>                 return len;
>         if (len == TPM_ERROR_SIZE) {
>                 err = be32_to_cpu(cmd->header.out.return_code);
>                 dev_dbg(chip->dev, "A TPM error (%d) occurred %s\n", err, desc);
>                 return err;
>         }
>         return 0;
> }
> 
> Where, desc comes from rc = tpm_getcap(dev, TPM_CAP_PROP_MANUFACTURER,
> &cap, "attempting to determine the manufacturer");
> 
> TPM_ERROR_SIZE is 10, looks like it satisfies that condition.
> 

Ahh yeah, I misread the code...

I guess then this error comes from the chip itself? Interesting that it
uses posix errors. Still though, it does seem like it's coming back
from resume in a bad state...

-- 
Jeff Layton <jlayton@...chiereds.net>
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