1 files changed, 19 insertions, 2 deletions

diff --git a/arch/arm/mach-omap2/pm44xx.c b/arch/arm/mach-omap2/pm44xx.c
index aa6fd98f606e..ea62e75ef21d 100644
--- a/arch/arm/mach-omap2/pm44xx.c
+++ b/arch/arm/mach-omap2/pm44xx.c
@@ -77,10 +77,20 @@ static int omap4_pm_suspend(void)
                 omap_set_pwrdm_state(pwrst->pwrdm, pwrst->saved_state);
                 pwrdm_set_logic_retst(pwrst->pwrdm, pwrst->saved_logic_state);
         }
-        if (ret)
+        if (ret) {
                 pr_crit("Could not enter target state in pm_suspend\n");
-        else
+                /*
+                 * OMAP4 chip PM currently works only with certain (newer)
+                 * versions of bootloaders. This is due to missing code in the
+                 * kernel to properly reset and initialize some devices.
+                 * Warn the user about the bootloader version being one of the
+                 * possible causes.
+                 * http://www.spinics.net/lists/arm-kernel/msg218641.html
+                 */
+                pr_warn("A possible cause could be an old bootloader - try u-boot >= v2012.07\n");
+        } else {
                 pr_info("Successfully put all powerdomains to target state\n");
+        }
 
         return 0;
 }
@@ -146,6 +156,13 @@ int __init omap4_pm_init(void)
         }
 
         pr_err("Power Management for TI OMAP4.\n");
+        /*
+         * OMAP4 chip PM currently works only with certain (newer)
+         * versions of bootloaders. This is due to missing code in the
+         * kernel to properly reset and initialize some devices.
+         * http://www.spinics.net/lists/arm-kernel/msg218641.html
+         */
+        pr_warn("OMAP4 PM: u-boot >= v2012.07 is required for full PM support\n");
 
         ret = pwrdm_for_each(pwrdms_setup, NULL);
         if (ret) {