OMAP3 SDRC: Fix freeze when scaling CORE dpll to < 83Mhz

This patch fixes a bug in the CORE dpll scaling sequence which was
errouneously clearing some bits in the SDRC DLLA CTRL register and
hence causing a freeze.  The issue was observed only on platforms
which scale CORE dpll to < 83Mhz and hence program the DLL in fixed
delay mode.

Issue reported by Limei Wang <E12499@motorola.com>, with debugging
assistance from Richard Woodruff <r-woodruff2@ti.com> and Girish
Ghongdemath <girishsg@ti.com>.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Cc: Limei Wang <E12499@motorola.com>
Cc: Richard Woodruff <r-woodruff2@ti.com>
Cc: Girish Ghongdemath <girishsg@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
[paul@pwsan.com: updated patch description to include collaboration credits]
This commit is contained in:
Rajendra Nayak 2009-07-24 19:44:01 -06:00 committed by paul
parent 75f251e3d0
commit 8ff120e530

View File

@ -143,7 +143,7 @@ return_to_sdram:
unlock_dll:
ldr r11, omap3_sdrc_dlla_ctrl
ldr r12, [r11]
and r12, r12, #FIXEDDELAY_MASK
bic r12, r12, #FIXEDDELAY_MASK
orr r12, r12, #FIXEDDELAY_DEFAULT
orr r12, r12, #DLLIDLE_MASK
str r12, [r11] @ (no OCP barrier needed)