[Qemu-devel] [PATCH v2] ACPI: Fix AppleSMC _STA size

[Gabriel L. Somlo]

Minimize the storage used for AppleSMC's _STA (8bit), relying on ASL
to implicitly convert it to the officially specified 32bit value.

Signed-off-by: Gabriel Somlo <address@hidden>
---

This applies incrementally on top of "Add DSDT node for AppleSMC" v.3
(accepted Dec. 25, 2013), and obsoletes everything I've sent out since :)

After some experimentation I realized ASL is flexible about the size of
its named variables, and happy to implicitly convert an 8bit value to
32 bits when needed. As such, I vote for the space saving option...

Thanks, and sorry for all the noise,
  Gabriel

 hw/i386/acpi-dsdt-isa.dsl |  4 ++--
 hw/i386/acpi-build.c      | 11 +++++------
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/hw/i386/acpi-dsdt-isa.dsl b/hw/i386/acpi-dsdt-isa.dsl
index 46942c1..3a6e100 100644
--- a/hw/i386/acpi-dsdt-isa.dsl
+++ b/hw/i386/acpi-dsdt-isa.dsl
@@ -19,8 +19,8 @@ Scope(\_SB.PCI0.ISA) {
     Device (SMC) {
         Name(_HID, EisaId("APP0001"))
         /* _STA will be patched to 0x0B if AppleSMC is present */
-        ACPI_EXTRACT_NAME_WORD_CONST DSDT_APPLESMC_STA
-        Name(_STA, 0xFF00)
+        ACPI_EXTRACT_NAME_BYTE_CONST DSDT_APPLESMC_STA
+        Name(_STA, 0xF0)
         Name(_CRS, ResourceTemplate () {
             IO (Decode16, 0x0300, 0x0300, 0x01, 0x20)
             IRQNoFlags() { 6 }
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 30bfcd2..9e5733e 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -81,7 +81,7 @@ typedef struct AcpiMiscInfo {
 
 static void acpi_get_dsdt(AcpiMiscInfo *info)
 {
-    unsigned short applesmc_sta_val, *applesmc_sta_off;
+    uint16_t *applesmc_sta;
     Object *piix = piix4_pm_find();
     Object *lpc = ich9_lpc_find();
     assert(!!piix != !!lpc);
@@ -89,18 +89,17 @@ static void acpi_get_dsdt(AcpiMiscInfo *info)
     if (piix) {
         info->dsdt_code = AcpiDsdtAmlCode;
         info->dsdt_size = sizeof AcpiDsdtAmlCode;
-        applesmc_sta_off = piix_dsdt_applesmc_sta;
+        applesmc_sta = piix_dsdt_applesmc_sta;
     }
     if (lpc) {
         info->dsdt_code = Q35AcpiDsdtAmlCode;
         info->dsdt_size = sizeof Q35AcpiDsdtAmlCode;
-        applesmc_sta_off = q35_dsdt_applesmc_sta;
+        applesmc_sta = q35_dsdt_applesmc_sta;
     }
 
     /* Patch in appropriate value for AppleSMC _STA */
-    applesmc_sta_val = applesmc_find() ? 0x0b : 0x00;
-    *(uint16_t *)(info->dsdt_code + *applesmc_sta_off) =
-        cpu_to_le16(applesmc_sta_val);
+    *(uint8_t *)(info->dsdt_code + *applesmc_sta) =
+        applesmc_find() ? 0x0b : 0x00;
 }
 
 static
-- 
1.8.1.4