OMAP3630: PM: Erratum i583: disable coreoff if < ES1.2
authorEduardo Valentin <eduardo.valentin@nokia.com>
Mon, 20 Dec 2010 20:05:09 +0000 (14:05 -0600)
committerKevin Hilman <khilman@deeprootsystems.com>
Tue, 21 Dec 2010 22:45:53 +0000 (14:45 -0800)
commitcc1b6028878646a2419b27e5f590b5e9fe01dc3d
tree560f6e797d20c112d1887d74250d41668b43b2ff
parent80723c3fe457a5d29c178da4ac72983f47b37ed7
OMAP3630: PM: Erratum i583: disable coreoff if < ES1.2

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>
arch/arm/mach-omap2/cpuidle34xx.c
arch/arm/mach-omap2/pm.h
arch/arm/mach-omap2/pm34xx.c