OMAP3: add comments for erratas i540 and i478 workarounds

Add comments and IDs for the following erratas:
- i540: MPU cannot exit from Standby,
- i478: Unexpected Cold-Reset is generated when device is coming
   back from OFF mode

Signed-off-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/arch/arm/mach-omap2/irq.c b/arch/arm/mach-omap2/irq.c
index 32eeabe..85bf8ca 100644 (file)
--- a/arch/arm/mach-omap2/irq.c
+++ b/arch/arm/mach-omap2/irq.c
@@ -284,7 +284,10 @@ void omap3_intc_suspend(void)
 
 void omap3_intc_prepare_idle(void)
 {
-       /* Disable autoidle as it can stall interrupt controller */
+       /*
+        * Disable autoidle as it can stall interrupt controller,
+        * cf. errata ID i540 for 3430 (all revisions up to 3.1.x)
+        */
        intc_bank_write_reg(0, &irq_banks[0], INTC_SYSCONFIG);
 }
 

diff --git a/arch/arm/mach-omap2/powerdomains34xx.h b/arch/arm/mach-omap2/powerdomains34xx.h
index fa90486..ce5c15b 100644 (file)
--- a/arch/arm/mach-omap2/powerdomains34xx.h
+++ b/arch/arm/mach-omap2/powerdomains34xx.h
@@ -80,6 +80,10 @@ static struct powerdomain mpu_3xxx_pwrdm = {
  * 3430s upto ES3.0 and 3630ES1.0. Hence this feature
  * needs to be disabled on these chips.
  * Refer: 3430 errata ID i459 and 3630 errata ID i579
+ *
+ * Note: setting the SAR flag could help for errata ID i478
+ *  which applies to 3430 <= ES3.1, but since the SAR feature
+ *  is broken, do not use it.
  */
 static struct powerdomain core_3xxx_pre_es3_1_pwrdm = {
        .name             = "core_pwrdm",
@@ -108,6 +112,10 @@ static struct powerdomain core_3xxx_es3_1_pwrdm = {
                                          CHIP_GE_OMAP3630ES1_1),
        .pwrsts           = PWRSTS_OFF_RET_ON,
        .pwrsts_logic_ret = PWRSTS_OFF_RET,
+       /*
+        * Setting the SAR flag for errata ID i478 which applies
+        *  to 3430 <= ES3.1
+        */
        .flags            = PWRDM_HAS_HDWR_SAR, /* for USBTLL only */
        .banks            = 2,
        .pwrsts_mem_ret   = {