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authorLv Zheng <lv.zheng@intel.com>2015-07-01 14:43:11 +0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-07-01 23:17:52 +0200
commitc04e1fb4396d27f18296db0f914760fa7fe8223a (patch)
treea5460ef5656d79d7331c7c6b80239d25f1cb2be6 /include/acpi/acpixf.h
parentaca2a5d3a8fce1879627bc4ec9d180b74ae512e2 (diff)
ACPICA: Tables: Enable both 32-bit and 64-bit FACS
ACPICA commit f7b86f35416e3d1f71c3d816ff5075ddd33ed486 The following commit is reported to have broken s2ram on some platforms: Commit: 0249ed2444d65d65fc3f3f64f398f1ad0b7e54cd ACPICA: Add option to favor 32-bit FADT addresses. The platform reports 2 FACS tables (which is not allowed by ACPI specification) and the new 32-bit address favor rule forces OSPMs to use the FACS table reported via FADT's X_FIRMWARE_CTRL field. The root cause of the reported bug might be one of the followings: 1. BIOS may favor the 64-bit firmware waking vector address when the version of the FACS is greater than 0 and Linux currently only supports resuming from the real mode, so the 64-bit firmware waking vector has never been set and might be invalid to BIOS while the commit enables higher version FACS. 2. BIOS may favor the FACS reported via the "FIRMWARE_CTRL" field in the FADT while the commit doesn't set the firmware waking vector address of the FACS reported by "FIRMWARE_CTRL", it only sets the firware waking vector address of the FACS reported by "X_FIRMWARE_CTRL". This patch excludes the cases that can trigger the bugs caused by the root cause 2. There is no handshaking mechanism can be used by OSPM to tell BIOS which FACS is currently used. Thus the FACS reported by "FIRMWARE_CTRL" may still be used by BIOS and the 0 value of the 32-bit firmware waking vector might trigger such failure. This patch tries to favor 32bit FACS address in another way where both the FACS reported by "FIRMWARE_CTRL" and the FACS reported by "X_FIRMWARE_CTRL" are loaded so that further commit can set firmware waking vector in the both tables to ensure we can exclude the cases that trigger the bugs caused by the root cause 2. The exclusion is split into 2 commits as this commit is also useful for dumping more ACPI tables, it won't get reverted when such exclusion is no longer necessary. Lv Zheng. Link: https://bugzilla.kernel.org/show_bug.cgi?id=74021 Link: https://github.com/acpica/acpica/commit/f7b86f35 Cc: 3.14.1+ <stable@vger.kernel.org> # 3.14.1+ Reported-and-tested-by: Oswald Buddenhagen <ossi@kde.org> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'include/acpi/acpixf.h')
-rw-r--r--include/acpi/acpixf.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h
index 821095ce5af7..445fd1e1688c 100644
--- a/include/acpi/acpixf.h
+++ b/include/acpi/acpixf.h
@@ -200,6 +200,15 @@ ACPI_INIT_GLOBAL(u8, acpi_gbl_do_not_use_xsdt, FALSE);
ACPI_INIT_GLOBAL(u8, acpi_gbl_use32_bit_fadt_addresses, TRUE);
/*
+ * Optionally use 32-bit FACS table addresses.
+ * It is reported that some platforms fail to resume from system suspending
+ * if 64-bit FACS table address is selected:
+ * https://bugzilla.kernel.org/show_bug.cgi?id=74021
+ * Default is TRUE, favor the 32-bit addresses.
+ */
+ACPI_INIT_GLOBAL(u8, acpi_gbl_use32_bit_facs_addresses, TRUE);
+
+/*
* Optionally truncate I/O addresses to 16 bits. Provides compatibility
* with other ACPI implementations. NOTE: During ACPICA initialization,
* this value is set to TRUE if any Windows OSI strings have been

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