[PATCH] Alchemy: fix reset for MTX-1 and XXS1500

[Florian Fainelli <florian@openwrt.org>]

Since commit 32fd6901 (MIPS: Alchemy: get rid of common/reset.c)
Alchemy-based boards use their own reset function. For MTX-1 and XXS1500,
the reset function pokes at the BCSR.SYSTEM_RESET register, but this does
not work. According to Bruno Randolf, this was not tested when written.

Previously, the generic au1000_restart() routine called the board specific
reset function, which for MTX-1 and XXS1500 did not work, but finally made
a jump to the reset vector, which really triggers a system restart. Fix
reboot for both targets by jumping to the reset vector.

CC: Bruno Randolf <br1@einfach.org>
CC: stable@kernel.org
Signed-off-by: Florian Fainelli <florian@openwrt.org>
---
Stable: 2.6.34+

diff --git a/arch/mips/alchemy/mtx-1/board_setup.c 
b/arch/mips/alchemy/mtx-1/board_setup.c
index 6398fa9..40b84b9 100644
--- a/arch/mips/alchemy/mtx-1/board_setup.c
+++ b/arch/mips/alchemy/mtx-1/board_setup.c
@@ -54,8 +54,8 @@ int mtx1_pci_idsel(unsigned int devsel, int assert);

 static void mtx1_reset(char *c)
 {
-       /* Hit BCSR.SYSTEM_CONTROL[SW_RST] */
-       au_writel(0x00000000, 0xAE00001C);
+       /* Jump to the reset vector */
+       __asm__ __volatile__("jr\t%0"::"r"(0xbfc00000));
 }

 static void mtx1_power_off(void)
diff --git a/arch/mips/alchemy/xxs1500/board_setup.c 
b/arch/mips/alchemy/xxs1500/board_setup.c
index b43c918..80c521e 100644
--- a/arch/mips/alchemy/xxs1500/board_setup.c
+++ b/arch/mips/alchemy/xxs1500/board_setup.c
@@ -36,8 +36,8 @@

 static void xxs1500_reset(char *c)
 {
-       /* Hit BCSR.SYSTEM_CONTROL[SW_RST] */
-       au_writel(0x00000000, 0xAE00001C);
+       /* Jump to the reset vector */
+       __asm__ __volatile__("jr\t%0"::"r"(0xbfc00000));
 }

 static void xxs1500_power_off(void)
--
1.7.1