Fix Cortex-M3 nested interrupt hard fault

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3119 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 8 insertions, 7 deletions

diff --git a/nuttx/arch/arm/src/lm3s/lm3s_vectors.S b/nuttx/arch/arm/src/lm3s/lm3s_vectors.S
index 5d6f7962e..b88b52c8b 100644
--- a/nuttx/arch/arm/src/lm3s/lm3s_vectors.S
+++ b/nuttx/arch/arm/src/lm3s/lm3s_vectors.S
@@ -607,7 +607,7 @@ lm3s_irqcommon:
 	 * values to the stack.

 	 */

 

-        add	r1, r0, #SW_XCPT_SIZE	/* R1=Address of HW save area in reg array */

+    add	r1, r0, #SW_XCPT_SIZE	/* R1=Address of HW save area in reg array */

 	ldmia	r1, {r4-r11}		/* Fetch eight registers in HW save area */

 	ldr	r1, [r0, #(4*REG_SP)]	/* R1=Value of SP before interrupt */

 	stmdb	r1!, {r4-r11}		/* Store eight registers in HW save area */

@@ -622,17 +622,18 @@ lm3s_irqcommon:
 2:

 	msr	msp, r1			/* Recover the return MSP value */

 

-	/* Do we need to restore interrupts? */

+	/* Restore the interrupt state.  Preload r14 with the special return

+	 * value first (so that the return actually occurs with interrupts

+	 * still disabled).

+	 */

 

-	tst	r3, #1			/* PRIMASK bit 1=1 means that interrupts are masked */

-	bne	3f

-	cpsie	i			/* Restore interrupts */

+	ldr	r14, =EXC_RETURN	/* Load the special value */

+	msr	primask, r3		/* Restore interrupts */

 

 	/* Always return with R14 containing the special value that will: (1)

 	 * return to thread mode, and (2) continue to use the MSP

 	 */

-3:

-	ldr	r14, =EXC_RETURN	/* Load the special value */

+

 	bx	r14			/* And return */

 	.size	handlers, .-handlers