In enter_acpi_mode() PM1_CNT register is changed to PM1_CNT_SCI_EN
directly without preserving its previous value. Update to change
the register access to read-modify-write (RMW).
Signed-off-by: Bin Meng <bmeng...@gmail.com>
Reviewed-by: Simon Glass <s...@chromium.org>
---
Changes in v2: None
arch/x86/lib/acpi_table.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/x86/lib/acpi_table.c b/arch/x86/lib/acpi_table.c
index f118345..8be8120 100644
--- a/arch/x86/lib/acpi_table.c
+++ b/arch/x86/lib/acpi_table.c
@@ -306,6 +306,8 @@ static void acpi_create_mcfg(struct acpi_mcfg *mcfg)
static void enter_acpi_mode(int pm1_cnt)
{
+ u16 val = inw(pm1_cnt);
+
/*
* PM1_CNT register bit0 selects the power management event to be
* either an SCI or SMI interrupt. When this bit is set, then power
@@ -320,7 +322,7 @@ static void enter_acpi_mode(int pm1_cnt)
* system, and expose ourselves to OSPM as working under ACPI mode
* already, turn this bit on.
*/
- outw(PM1_CNT_SCI_EN, pm1_cnt);
+ outw(val | PM1_CNT_SCI_EN, pm1_cnt);
}
/*
--
2.9.2
_______________________________________________
U-Boot mailing list
U-Boot@lists.denx.de
https://lists.denx.de/listinfo/u-boot
