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-rw-r--r--arch/x86/cpu/baytrail/valleyview.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/x86/cpu/baytrail/valleyview.c b/arch/x86/cpu/baytrail/valleyview.c
index c58f6a8..9af1bda 100644
--- a/arch/x86/cpu/baytrail/valleyview.c
+++ b/arch/x86/cpu/baytrail/valleyview.c
@@ -10,6 +10,13 @@
#include <asm/irq.h>
#include <asm/mrccache.h>
#include <asm/post.h>
+#include <asm/arch/iomap.h>
+
+/* GPIO SUS */
+#define GPIO_SUS_PAD_BASE (IO_BASE_ADDRESS + IO_BASE_OFFSET_GPSSUS)
+#define GPIO_SUS_DFX5_CONF0 0x150
+#define BYT_TRIG_LVL BIT(24)
+#define BYT_TRIG_POS BIT(25)
#ifndef CONFIG_EFI_APP
int arch_cpu_init(void)
@@ -33,6 +40,21 @@ int arch_misc_init(void)
mrccache_save();
#endif
+ /*
+ * For some unknown reason, FSP (gold4) for BayTrail configures
+ * the GPIO DFX5 PAD to enable level interrupt (bit 24 and 25).
+ * This does not cause any issue when Linux kernel runs w/ or w/o
+ * the pinctrl driver for BayTrail. However this causes unstable
+ * S3 resume if the pinctrl driver is included in the kernel build.
+ * As this pin keeps generating interrupts during an S3 resume,
+ * and there is no IRQ requester in the kernel to handle it, the
+ * kernel seems to hang and does not continue resuming.
+ *
+ * Clear the mysterious interrupt bits for this pin.
+ */
+ clrbits_le32(GPIO_SUS_PAD_BASE + GPIO_SUS_DFX5_CONF0,
+ BYT_TRIG_LVL | BYT_TRIG_POS);
+
return 0;
}