OMAP3: add comments for low power code errata

Errata covered:
- 1.157 & 1.185
- i443
- i581

Tested on N900 and Beagleboard with full RET and OFF modes,
using cpuidle and suspend.

Signed-off-by: Jean Pihet <j-pihet@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/sleep34xx.S b/arch/arm/mach-omap2/sleep34xx.S
index 06e47326e17c..17dfe30db3a7 100644
--- a/arch/arm/mach-omap2/sleep34xx.S
+++ b/arch/arm/mach-omap2/sleep34xx.S
@@ -596,6 +596,7 @@ usettbr0:
  * Internal functions
  */
 
+/* This function implements the erratum ID i443 WA, applies to 34xx >= ES3.0 */
         .text
 ENTRY(es3_sdrc_fix)
         ldr     r4, sdrc_syscfg         @ get config addr
@@ -641,6 +642,16 @@ sdrc_manual_1:
 ENTRY(es3_sdrc_fix_sz)
         .word   . - es3_sdrc_fix
 
+/*
+ * This function implements the erratum ID i581 WA:
+ *  SDRC state restore before accessing the SDRAM
+ *
+ * Only used at return from non-OFF mode. For OFF
+ * mode the ROM code configures the SDRC and
+ * the DPLL before calling the restore code directly
+ * from DDR.
+ */
+
 /* Make sure SDRC accesses are ok */
 wait_sdrc_ok: