3 files changed, 71 insertions, 2 deletions

diff --git a/arch/arm/mach-omap2/pm-debug-regs.c b/arch/arm/mach-omap2/pm-debug-regs.c
index 0997fe8138d..42c40d92427 100644
--- a/arch/arm/mach-omap2/pm-debug-regs.c
+++ b/arch/arm/mach-omap2/pm-debug-regs.c
@@ -134,6 +134,15 @@ static void pm_dbg_regset_store(u32 *ptr)
 	}
 }
 
+void pm_dbg_regs_copy(int tgt, int src)
+{
+	size_t sz = pm_dbg_get_regset_size();
+
+	pr_debug("saved reference copy %s(%d, %d) size = %u <- %pS\n",
+		__func__, tgt, src, sz, __builtin_return_address(0));
+	memcpy(pm_dbg_reg_set[tgt - 1], pm_dbg_reg_set[src - 1], sz);
+}
+
 void pm_dbg_regs_save(int reg_set)
 {
 	if (pm_dbg_reg_set[reg_set - 1] == NULL)
@@ -424,6 +433,50 @@ int pm_dbg_regs_dump(int reg_set)
 }
 EXPORT_SYMBOL(pm_dbg_regs_dump);
 
+int pm_dbg_regs_dump_delta(int cur, int ref)
+{
+	int i, j;
+	unsigned long val_cur;
+	u32 *ptr_cur;
+	unsigned long val_ref;
+	u32 *ptr_ref;
+
+	if ((cur <= 0) || (cur > PM_DBG_MAX_REG_SETS) ||
+	    (ref <= 0) || (ref > PM_DBG_MAX_REG_SETS)) {
+		return -EINVAL;
+	}
+
+	ptr_cur = pm_dbg_reg_set[cur - 1];
+	ptr_ref = pm_dbg_reg_set[ref - 1];
+
+	i = 0;
+
+	pr_debug("   module      ( address) reg        %d          %d\n",
+			cur, ref);
+	while (pm_dbg_reg_modules[i].name[0] != 0) {
+		bool cm = pm_dbg_reg_modules[i].type == MOD_CM;
+		uint32_t addr = (u32)(OMAP3430_CM_BASE +
+				pm_dbg_reg_modules[i].offset);
+
+		for (j = pm_dbg_reg_modules[i].low;
+		     j <= pm_dbg_reg_modules[i].high; j += 4) {
+			val_cur = *(ptr_cur++);
+			val_ref = *(ptr_ref++);
+			if (val_cur != val_ref) {
+				pr_debug("MOD: %s_%-4s %s(%08x) "
+					"%02x => 0x%08lx 0x%08lx\n",
+					cm ? "CM_" : "PRM_",
+					pm_dbg_reg_modules[i].name,
+					cm ? " " : "",
+					addr, j, val_cur, val_ref);
+			}
+		}
+		i++;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(pm_dbg_regs_dump_delta);
+
 static void __init pm_dbg_regset_init(void)
 {
 	int i;
diff --git a/arch/arm/mach-omap2/pm-debug-regs.h b/arch/arm/mach-omap2/pm-debug-regs.h
index e403977affa..f70bbe5c6a8 100644
--- a/arch/arm/mach-omap2/pm-debug-regs.h
+++ b/arch/arm/mach-omap2/pm-debug-regs.h
@@ -20,12 +20,16 @@
 extern int  pm_dbg_regs_init(struct dentry *d);
 extern void pm_dbg_regs_save(int reg_set);
 extern void pm_dbg_regs_dump(int reg_set);
+extern void pm_dbg_regs_dump_delta(int cur, int rfr);
 extern void pm_dbg_show_wakeup_source(void);
+extern void pm_dbg_regs_copy(int tgt, int src);
 #else
 static inline int pm_dbg_regs_init(struct dentry *d) { return 0; }
 static inline void pm_dbg_regs_save(int reg_set) {};
 static inline void pm_dbg_regs_dump(int reg_set) {};
+static inline void pm_dbg_regs_dump_delta(int current, int ref) {}
 static inline void pm_dbg_show_wakeup_source(void) {};
+static inline void pm_dbg_regs_copy(int tgt, int src) {};
 #endif
 
 #endif
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index afe15f00637..6daf94a0223 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -62,6 +62,7 @@
 /* pm34xx errata defined in pm.h */
 u16 pm34xx_errata;
 bool suspend_debug;
+bool suspend_offmode_ref_saved;
 
 struct power_state {
 	struct powerdomain *pwrdm;
@@ -391,6 +392,12 @@ void omap_sram_idle(bool in_suspend)
 			omap3_cm_restore_context();
 			omap3_sram_restore_context();
 			omap2_sms_restore_context();
+
+			if (unlikely(!suspend_offmode_ref_saved)) {
+				suspend_offmode_ref_saved = true;
+				pm_dbg_regs_copy(3, 1);
+				pm_dbg_regs_copy(4, 2);
+			}
 		}
 		if (core_next_state == PWRDM_POWER_OFF) {
 			omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK,
@@ -457,8 +464,13 @@ restore:
 	}
 	if (ret) {
 		pr_err("Could not enter target state in pm_suspend\n");
-		pm_dbg_regs_dump(1);
-		pm_dbg_regs_dump(2);
+		if (suspend_offmode_ref_saved) {
+			pm_dbg_regs_dump_delta(1, 3);
+			pm_dbg_regs_dump_delta(2, 4);
+		} else {
+			pm_dbg_regs_dump(1);
+			pm_dbg_regs_dump(2);
+		}
 	} else
 		pr_info("Successfully put all powerdomains to target state\n");