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OMAP3630: PM: Erratum i583: disable coreoff if < ES1.2

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Limitation i583: Self_Refresh Exit issue after OFF mode

Issue:
When device is waking up from OFF mode, then SDRC state machine sends
inappropriate sequence violating JEDEC standards.

Impact:
OMAP3630 < ES1.2 is impacted as follows depending on the platform:
CS0: for 38.4MHz as internal sysclk, DDR content seen to be stable, while
	for all other sysclk frequencies, varied levels of instability
	seen based on varied parameters.
CS1: impacted

This patch takes option #3 as recommended by the Silicon erratum:
Avoid core power domain transitioning to OFF mode. Power consumption
impact is expected in this case.
To do this, we route core OFF requests to RET request on the impacted
revisions of silicon.

Acked-by: Jean Pihet <j-pihet@ti.com>

[nm@ti.com: rebased the code to 2.6.37-rc2- short circuit code changed a bit]
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Eduardo Valentin <eduardo.valentin@nokia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
This commit is contained in:
Eduardo Valentin
2010-12-20 14:05:09 -06:00
committed by Kevin Hilman
parent 80723c3fe4
commit cc1b602887
3 changed files with 35 additions and 3 deletions
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arch/arm/mach-omap2/pm.h
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@@ -86,6 +86,7 @@ extern unsigned int omap24xx_cpu_suspend_sz;
extern unsigned int omap34xx_cpu_suspend_sz;
#define PM_RTA_ERRATUM_i608 (1 << 0)
#define PM_SDRC_WAKEUP_ERRATUM_i583 (1 << 1)
#if defined(CONFIG_PM) && defined(CONFIG_ARCH_OMAP3)
extern u16 pm34xx_errata;