OMAP2/3 SDRC: don't set SDRC_POWER.PWDENA on boot

Stop setting SDRC_POWER.PWDENA on boot.  There is a nasty erratum
(34xx erratum 1.150) that can cause memory corruption if PWDENA is
enabled.

Based originally on a patch from Samu P. Onkalo <samu.p.onkalo@nokia.com>.

Tested on BeagleBoard rev C2.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Samu P. Onkalo <samu.p.onkalo@nokia.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/arch/arm/mach-omap2/sdrc.c b/arch/arm/mach-omap2/sdrc.c
index 2e9e38db30e9..9e3bd4fa7810 100644
--- a/arch/arm/mach-omap2/sdrc.c
+++ b/arch/arm/mach-omap2/sdrc.c
@@ -125,8 +125,11 @@ void __init omap2_sdrc_init(struct omap_sdrc_params *sdrc_cs0,
         sdrc_init_params_cs1 = sdrc_cs1;
 
         /* XXX Enable SRFRONIDLEREQ here also? */
+        /*
+         * PWDENA should not be set due to 34xx erratum 1.150 - PWDENA
+         * can cause random memory corruption
+         */
         l = (1 << SDRC_POWER_EXTCLKDIS_SHIFT) |
-                (1 << SDRC_POWER_PWDENA_SHIFT) |
                 (1 << SDRC_POWER_PAGEPOLICY_SHIFT);
         sdrc_write_reg(l, SDRC_POWER);
 }