diff mbox

[U-Boot,4/4] ARM: tegra: simplify halt_avp()

Message ID 1391461407-21529-4-git-send-email-swarren@wwwdotorg.org
State Accepted
Delegated to: Tom Warren
Headers show

Commit Message

Stephen Warren Feb. 3, 2014, 9:03 p.m. UTC 
From: Stephen Warren <swarren@nvidia.com>

In order to completely halt the AVP processor, we should simply write
FLOW_MODE_STOP without any extra options that allow wakeup. Amend the
code to do this.

I believe that enabling FIQ_1 and IRQ_1 allow the CPU to be awoken by
interrupts. We don't want this; if later SW wishes to use the AVP, it
should be reset and booted from scratch.

Related, the bits that were previously IRQ_1 and FIQ_1 have a slightly
different definition starting with Tegra114, so the values we're
writing don't entirely make sense there anyway.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
 arch/arm/cpu/arm720t/tegra-common/cpu.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

Comments

Stephen Warren Feb. 27, 2014, 5:19 p.m. UTC | #1 
On 02/03/2014 02:03 PM, Stephen Warren wrote:
> From: Stephen Warren <swarren@nvidia.com>
> 
> In order to completely halt the AVP processor, we should simply write
> FLOW_MODE_STOP without any extra options that allow wakeup. Amend the
> code to do this.
> 
> I believe that enabling FIQ_1 and IRQ_1 allow the CPU to be awoken by
> interrupts. We don't want this; if later SW wishes to use the AVP, it
> should be reset and booted from scratch.
> 
> Related, the bits that were previously IRQ_1 and FIQ_1 have a slightly
> different definition starting with Tegra114, so the values we're
> writing don't entirely make sense there anyway.

Tom, does this series look good? I'd really like to get these fixes into
2014.04 so that it can boot on our simulator without any local patches.
Thanks.
diff mbox

Patch

diff --git a/arch/arm/cpu/arm720t/tegra-common/cpu.c b/arch/arm/cpu/arm720t/tegra-common/cpu.c
index 2c5cd63917d3..168f525ec7c8 100644
--- a/arch/arm/cpu/arm720t/tegra-common/cpu.c
+++ b/arch/arm/cpu/arm720t/tegra-common/cpu.c
@@ -378,8 +378,7 @@  void clock_enable_coresight(int enable)
 void halt_avp(void)
 {
 	for (;;) {
-		writel((HALT_COP_EVENT_JTAG | HALT_COP_EVENT_IRQ_1 \
-			| HALT_COP_EVENT_FIQ_1 | (FLOW_MODE_STOP<<29)),
-			FLOW_CTLR_HALT_COP_EVENTS);
+		writel(HALT_COP_EVENT_JTAG | (FLOW_MODE_STOP << 29),
+		       FLOW_CTLR_HALT_COP_EVENTS);
 	}
 }