Rafael J. Wysocki f759546498 ACPI / TPM: Fix resume regression on Chromebooks ... Chromebooks (at least Acer C720 and Pixel) implement an ACPI object for TPM, but don't implement the _DSM method to support PPI. As a result, the TPM driver fails to load on those machines after commit 1569a4c4ce (ACPI / TPM: detect PPI features by checking availability of _DSM functions) which causes them to fail to resume from system suspend, becuase they require the TPM hardware to be put into the right state during resume and the TPM driver is necessary for that. Fix the problem by making tpm_add_ppi() return 0 when tpm_ppi_handle is still NULL after walking the ACPI namespace in search for the PPI _DSM, which allows the TPM driver to load and operate the hardware (during system resume in particular), but avoid creating the PPI sysfs group in that case. This change is based on a prototype patch from Jiang Liu. Fixes: 1569a4c4ce (ACPI / TPM: detect PPI features by checking availability of _DSM functions) References: https://bugzilla.kernel.org/show_bug.cgi?id=74021 Reported-by: James Duley <jagduley@gmail.com> Reported-by: Phillip Dixon <phil@dixon.gen.nz> Tested-by: Brandon Casey <drafnel@gmail.com> Cc: 3.14+ <stable@vger.kernel.org> # 3.14+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>		2014-05-12 01:13:28 +02:00
..
Kconfig	Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP	2014-04-07 16:36:11 -07:00
Makefile	…
tpm-dev.c	…
tpm-interface.c	…
tpm-sysfs.c	…
tpm.h	…
tpm_acpi.c	…
tpm_atmel.c	…
tpm_atmel.h	…
tpm_eventlog.c	…
tpm_eventlog.h	…
tpm_i2c_atmel.c	…
tpm_i2c_infineon.c	drivers/char: delete non-required instances of include <linux/init.h>	2014-02-07 15:10:19 -08:00
tpm_i2c_nuvoton.c	…
tpm_i2c_stm_st33.c	drivers/char: delete non-required instances of include <linux/init.h>	2014-02-07 15:10:19 -08:00
tpm_i2c_stm_st33.h	…
tpm_ibmvtpm.c	…
tpm_ibmvtpm.h	…
tpm_infineon.c	…
tpm_nsc.c	…
tpm_of.c	…
tpm_ppi.c	ACPI / TPM: Fix resume regression on Chromebooks	2014-05-12 01:13:28 +02:00
tpm_tis.c	…
xen-tpmfront.c	…