Messages in this thread | | | Date | Tue, 22 Aug 2023 09:05:13 -0500 | Subject | Re: [PATCH v2] tpm: Don't make vendor check required for probe | From | Mario Limonciello <> |
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On 8/22/2023 08:22, Jarkko Sakkinen wrote: > On Mon Aug 21, 2023 at 5:02 PM EEST, Mario Limonciello wrote: >> The vendor check introduced by commit 554b841d4703 ("tpm: Disable RNG for >> all AMD fTPMs") doesn't work properly on a number of Intel fTPMs. On the >> reported systems the TPM doesn't reply at bootup and returns back the >> command code. This makes the TPM fail probe. >> >> As this isn't crucial for anything but AMD fTPM and AMD fTPM works, check >> the chip vendor and if it's not AMD don't run the checks. >> >> Cc: stable@vger.kernel.org >> Fixes: 554b841d4703 ("tpm: Disable RNG for all AMD fTPMs") >> Reported-by: Todd Brandt <todd.e.brandt@intel.com> >> Reported-by: Patrick Steinhardt <ps@pks.im> >> Reported-by: Ronan Pigott <ronan@rjp.ie> >> Reported-by: Raymond Jay Golo <rjgolo@gmail.com> >> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217804 >> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> >> --- >> v1->v2: >> * Check x86 vendor for AMD >> --- >> drivers/char/tpm/tpm_crb.c | 7 ++++++- >> 1 file changed, 6 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c >> index 9eb1a18590123..7faf670201ccc 100644 >> --- a/drivers/char/tpm/tpm_crb.c >> +++ b/drivers/char/tpm/tpm_crb.c >> @@ -465,8 +465,12 @@ static bool crb_req_canceled(struct tpm_chip *chip, u8 status) >> >> static int crb_check_flags(struct tpm_chip *chip) >> { >> + int ret = 0; >> +#ifdef CONFIG_X86 >> u32 val; >> - int ret; >> + >> + if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) >> + return ret; >> >> ret = crb_request_locality(chip, 0); >> if (ret) >> @@ -481,6 +485,7 @@ static int crb_check_flags(struct tpm_chip *chip) >> >> release: >> crb_relinquish_locality(chip, 0); >> +#endif > > Looks much better but the main question here is that is this combination > possible: > > 1. AMD CPU > 2. Non-AMD fTPM (i.e. manufacturer property differs) > > BR, Jarkko
Yes that combination is possible.
Pluton TPM uses the tpm_crb driver.
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