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>

diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index a81ed251e6672695c4c5efef605e3020197960e9..c45b4fa1deeb3ef0ee8dea63b656f3b522352cb6 100644 (file)
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -146,7 +146,7 @@ static void omap3_core_save_context(void)
 
        /*
         * Force write last pad into memory, as this can fail in some
-        * cases according to erratas 1.157, 1.185
+        * cases according to errata 1.157, 1.185
         */
        omap_ctrl_writel(omap_ctrl_readl(OMAP343X_PADCONF_ETK_D14),
                OMAP343X_CONTROL_MEM_WKUP + 0x2a0);
@@ -433,7 +433,7 @@ void omap_sram_idle(void)
        /*
        * On EMU/HS devices ROM code restores a SRDC value
        * from scratchpad which has automatic self refresh on timeout
-       * of AUTO_CNT = 1 enabled. This takes care of errata 1.142.
+       * of AUTO_CNT = 1 enabled. This takes care of erratum ID i443.
        * Hence store/restore the SDRC_POWER register here.
        */
        if (omap_rev() >= OMAP3430_REV_ES3_0 &&

diff --git a/arch/arm/mach-omap2/sleep34xx.S b/arch/arm/mach-omap2/sleep34xx.S
index 06e47326e17cf29f6368bbe1e561665a0d3d2592..17dfe30db3a7d1f6f8ace83f9b026c6d5b46073d 100644 (file)
--- 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: