linux-mips
[Top] [All Lists]

[PATCH 1/3] MIPS: BCM47XX: do not use cpu_wait instruction on BCM4706

To: ralf@linux-mips.org, blogic@openwrt.org
Subject: [PATCH 1/3] MIPS: BCM47XX: do not use cpu_wait instruction on BCM4706
From: Hauke Mehrtens <hauke@hauke-m.de>
Date: Sun, 22 Dec 2013 14:36:30 +0100
Cc: linux-mips@linux-mips.org, Hauke Mehrtens <hauke@hauke-m.de>
List-archive: <http://www.linux-mips.org/archives/linux-mips/>
List-help: <mailto:ecartis@linux-mips.org?Subject=help>
List-id: linux-mips <linux-mips.eddie.linux-mips.org>
List-owner: <mailto:ralf@linux-mips.org>
List-post: <mailto:linux-mips@linux-mips.org>
List-software: Ecartis version 1.0.0
List-subscribe: <mailto:ecartis@linux-mips.org?subject=subscribe%20linux-mips>
List-unsubscribe: <mailto:ecartis@linux-mips.org?subject=unsubscribe%20linux-mips>
Original-recipient: rfc822;linux-mips@linux-mips.org
Sender: linux-mips-bounce@linux-mips.org
The BCM4706 has a problem with the CPU wait instruction. When r4k_wait
or r4k_wait_irqoff is used will just hang and not return from a
msleep(). Removing the cpu_wait functionality is a workaround for this
problem. The BCM4716 does not have this problem.

The BCM4706 SoC uses a MIPS 74K V4.9 CPU.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
---
 arch/mips/bcm47xx/setup.c |   10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/mips/bcm47xx/setup.c b/arch/mips/bcm47xx/setup.c
index 2ecb6ee..111be0b 100644
--- a/arch/mips/bcm47xx/setup.c
+++ b/arch/mips/bcm47xx/setup.c
@@ -34,6 +34,7 @@
 #include <linux/ssb/ssb_embedded.h>
 #include <linux/bcma/bcma_soc.h>
 #include <asm/bootinfo.h>
+#include <asm/idle.h>
 #include <asm/prom.h>
 #include <asm/reboot.h>
 #include <asm/time.h>
@@ -201,6 +202,15 @@ static void __init bcm47xx_register_bcma(void)
                panic("Failed to initialize BCMA bus (err %d)", err);
 
        bcm47xx_fill_bcma_boardinfo(&bcm47xx_bus.bcma.bus.boardinfo, NULL);
+
+       /* The BCM4706 has a problem with the CPU wait instruction.
+        * When r4k_wait or r4k_wait_irqoff is used will just hang and 
+        * not return from a msleep(). Removing the cpu_wait 
+        * functionality is a workaround for this problem. The BCM4716 
+        * does not have this problem.
+        */
+       if (bcm47xx_bus.bcma.bus.chipinfo.id == BCMA_CHIP_ID_BCM4706)
+               cpu_wait = NULL;
 }
 #endif
 
-- 
1.7.10.4


<Prev in Thread] Current Thread [Next in Thread>