On Wed Aug 23, 2023 at 12:28 AM EEST, Jerry Snitselaar wrote:
On Tue, Aug 22, 2023 at 11:39:12PM +0300, Jarkko Sakkinen 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.
Since only Microsoft Pluton is the only known combination of AMD CPU and fTPM from other vendor, disable hwrng otherwise. In order to make sysadmin aware of this, print also info message to the klog.
Cc: stable@vger.kernel.org Fixes: 554b841d4703 ("tpm: Disable RNG for all AMD fTPMs") Reported-by: Todd Brandt todd.e.brandt@intel.com Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217804 Signed-off-by: Jarkko Sakkinen jarkko@kernel.org
v2:
- CONFIG_X86
Did you mean to wrap the crb_acpi_add chunk with CONFIG_X86?
Yup :-/
$ git diff diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c index 28448bfd4062..ea085b14ab7c 100644 --- a/drivers/char/tpm/tpm_crb.c +++ b/drivers/char/tpm/tpm_crb.c @@ -805,12 +805,14 @@ static int crb_acpi_add(struct acpi_device *device) if (rc) goto out;
+#ifdef CONFIG_X86 /* A quirk for https://www.amd.com/en/support/kb/faq/pa-410 */ if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD && priv->sm != ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) { dev_info(dev, "Disabling hwrng\n"); chip->flags |= TPM_CHIP_FLAG_HWRNG_DISABLED; } +#endif /* CONFIG_X86 */
rc = tpm_chip_register(chip);
[also linux-sgx leaked by mistake to my git-send-email command line]
I sent a new one: https://lkml.org/lkml/2023/8/22/1288
BR, Jarkko