Re: TPM chip prevents machine from suspending

Sisir Koppaka
2011-03-28T20:32:59Z

On Tue, Mar 29, 2011 at 1:46 AM, Jeff Layton <jlayton@poochiereds.net> wrote:
> On Tue, 29 Mar 2011 01:27:05 +0530
> Sisir Koppaka <sisir.koppaka@gmail.com> wrote:
>
>> On Tue, Mar 29, 2011 at 1:15 AM, Jeff Layton <jlayton@poochiereds.net> wrote:
>> > On Mon, 28 Mar 2011 14:12:41 -0400
>> > Jeff Layton <jlayton@poochiereds.net> wrote:
>> >
>> >> On Mon, 28 Mar 2011 13:25:06 -0400
>> >> Stefan Berger <stefanb@linux.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...
>

Yup, it looks like the chip is at fault. The chip isn't supplying an
appropriate value for the capability TPM_CAP_PROP_MANUFACTURER (See
page 2 of [1], and compare with drivers/tpm/tpm.c). What is not clear
is whether the fault in the chip's response is due to the driver
code(maybe due to a firmware update etc.) or due to actual hardware
corruption.

http://www.trustedcomputinggroup.org/files/resource_files/137A54A3-1A4B-B294-D088F24684D141E1/Vendor%20ID%20Registry_0.1.pdf

sk