[ARM] S3C: Tidy sleep code path to fix call flow

As noted by Russell King, the sleep code path is not
elegant and makes use of leaving items on the stack
between calls.

Change the code that does the following:

        if (s3c_cpu_save(regs_save) == 0) {
                flush_cache_all();
                S3C_PMDBG("preparing to sleep\n");
                pm_cpu_sleep();
        }

to simply call s3c_cpu_save, and let that do the
necessary calls to quiesce and sleep the system.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

2 files changed, 19 insertions, 9 deletions

diff --git a/arch/arm/plat-s3c/include/plat/pm.h b/arch/arm/plat-s3c/include/plat/pm.h
index 5ee26da2702..3779775133a 100644
--- a/arch/arm/plat-s3c/include/plat/pm.h
+++ b/arch/arm/plat-s3c/include/plat/pm.h
@@ -162,5 +162,13 @@ extern void s3c_pm_restore_gpios(void);
  */
 extern void s3c_pm_save_gpios(void);
 
+/**
+ * s3c_pm_cb_flushcache - callback for assembly code
+ *
+ * Callback to issue flush_cache_all() as this call is
+ * not a directly callable object.
+ */
+extern void s3c_pm_cb_flushcache(void);
+
 extern void s3c_pm_save_core(void);
 extern void s3c_pm_restore_core(void);
diff --git a/arch/arm/plat-s3c/pm.c b/arch/arm/plat-s3c/pm.c
index a0ca18a75b0..061182ca66e 100644
--- a/arch/arm/plat-s3c/pm.c
+++ b/arch/arm/plat-s3c/pm.c
@@ -229,7 +229,7 @@ void (*pm_cpu_sleep)(void);
 
 static int s3c_pm_enter(suspend_state_t state)
 {
-	unsigned long regs_save[16];
+	static unsigned long regs_save[16];
 
 	/* ensure the debug is initialised (if enabled) */
 
@@ -289,15 +289,11 @@ static int s3c_pm_enter(suspend_state_t state)
 
 	s3c_pm_arch_stop_clocks();
 
-	/* s3c2410_cpu_save will also act as our return point from when
-	 * we resume as it saves its own register state, so use the return
-	 * code to differentiate return from save and return from sleep */
+	/* s3c_cpu_save will also act as our return point from when
+	 * we resume as it saves its own register state and restores it
+	 * during the resume.  */
 
-	if (s3c_cpu_save(regs_save) == 0) {
-		flush_cache_all();
-		S3C_PMDBG("preparing to sleep\n");
-		pm_cpu_sleep();
-	}
+	s3c_cpu_save(regs_save);
 
 	/* restore the cpu state using the kernel's cpu init code. */
 
@@ -325,6 +321,12 @@ static int s3c_pm_enter(suspend_state_t state)
 	return 0;
 }
 
+/* callback from assembly code */
+void s3c_pm_cb_flushcache(void)
+{
+	flush_cache_all();
+}
+
 static int s3c_pm_prepare(void)
 {
 	/* prepare check area if configured */