MIPS: BCM47XX: Fix reboot problem on BCM4705/BCM4785

This adds some code based on code from the Broadcom GPL tar to fix the
reboot problems on BCM4705/BCM4785. I tried rebooting my device for ~10
times and have never seen a problem. This reverts the changes in the
previous commit and adds the real fix as suggested by Rafał.

Setting bit 22 in Reg 22, sel 4 puts the BIU (Bus Interface Unit) into
async mode.

The previous commit was 316cad5c1d4daee998cd1f83ccdb437f6f20d45c [MIPS:
BCM47XX: make reboot more relaiable]

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Cc: jogo@openwrt.org
Cc: zajec5@gmail.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7545/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 11 insertions, 2 deletions

diff --git a/arch/mips/bcm47xx/setup.c b/arch/mips/bcm47xx/setup.c
index 2b63e7e7d3d3..ad439c273003 100644
--- a/arch/mips/bcm47xx/setup.c
+++ b/arch/mips/bcm47xx/setup.c
@@ -59,12 +59,21 @@ static void bcm47xx_machine_restart(char *command)
         switch (bcm47xx_bus_type) {
 #ifdef CONFIG_BCM47XX_SSB
         case BCM47XX_BUS_TYPE_SSB:
-                ssb_watchdog_timer_set(&bcm47xx_bus.ssb, 3);
+                if (bcm47xx_bus.ssb.chip_id == 0x4785)
+                        write_c0_diag4(1 << 22);
+                ssb_watchdog_timer_set(&bcm47xx_bus.ssb, 1);
+                if (bcm47xx_bus.ssb.chip_id == 0x4785) {
+                        __asm__ __volatile__(
+                                ".set\tmips3\n\t"
+                                "sync\n\t"
+                                "wait\n\t"
+                                ".set\tmips0");
+                }
                 break;
 #endif
 #ifdef CONFIG_BCM47XX_BCMA
         case BCM47XX_BUS_TYPE_BCMA:
-                bcma_chipco_watchdog_timer_set(&bcm47xx_bus.bcma.bus.drv_cc, 3);
+                bcma_chipco_watchdog_timer_set(&bcm47xx_bus.bcma.bus.drv_cc, 1);
                 break;
 #endif
         }