OMAP4430/60: EMIF: errata: Prohibit usage of Power-Down mode

A ZQ calibration long command is issued every time on exit
from active power-down and precharge power-down modes
when EMIF is configured to use Power-down mode
(EMIF_PWR_MGMT_CTRL.REG_LP_MODE=0x4).

Due to very short periods of power-down cycles, ZQ calibration
overhead creates bandwidth issues and increases overall system
power consumption.

As result, the guideline is to not allow Power-down mode and,
therefore, to not have set the
EMIF_PWR_MGMT_CTRL[10:8] REG_LP_MODE bit field to 0x4.

TI Errata i743; IMPACTED: OMAP4430/60 all revisions

Change-Id: Ib82f28e6e0c6c046ea277b90a78dc82c1ee82417
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Vitaly Chernooky <vitaly.chernooky@ti.com>

commit 3d198ff06f31cd283e62f629624c3baee51bef37 1 parent 8d60d6aaf0
grygoriyS authored 9 months ago Gerrit Code Review committed 2 months ago
ARM: OMAP4: cpuidle: Configure MPU C4 state to OSWR

Due to MPU_EMIF_NO_DYNDEP_IDLE_iXXX, MPU->EMIF dynamic dependency
is disabled when going to LP mode. This allows us to enable deeper
power state for MPU as MPU can transition to lower power state
independent of core power domain. We have observed 1.5mA saving in
OS Idle Screen on use case.

Change-Id: If4ec4426626dabf810b1f21ed33cdabafa386d5f
Signed-off-by: Madhusudan Chittim <c-madhu@ti.com>

commit 99e1e80a3db758657ac308b3236cc41401970018 1 parent e1b152cd3b
Madhusudan Chittim authored a year ago