• Tony Lindgren's avatar
    ARM: OMAP2+: Fix omap off idle power consumption creeping up · 102bcb6e
    Tony Lindgren authored
    If we use a combination of VMODE and I2C4 for retention modes,
    eventually the off idle power consumption will creep up by about
    23mW, even during off mode with I2C4 always staying enabled.
    
    Turns out this is because of erratum i531 "Extra Power Consumed
    When Repeated Start Operation Mode Is Enabled on I2C Interface
    Dedicated for Smart Reflex (I2C4)" as pointed out by Nishanth
    Menon <nm@ti.com>.
    
    Let's fix the issue by adding i2c_cfg_clear_mask for the bits
    to clear when initializing the I2C4 adapter so we can clear
    SREN bit that drives the I2C4 lines low otherwise when there
    is no traffic.
    
    Fixes: 3b8c4ebb ("ARM: OMAP3: Fix idle mode signaling for
    Cc: stable@vger.kernel.org # v3.16+
    sys_clkreq and sys_off_mode")
    Cc: Kevin Hilman <khilman@kernel.org>
    Cc: Tero Kristo <t-kristo@ti.com>
    Reviewed-by: default avatarNishanth Menon <nm@ti.com>
    Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
    102bcb6e
prm-regbits-34xx.h 6.22 KB