Blackfin arch: Fix bug - This change eliminates impact on application debugging

Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index eceb484..3db2f4d 100644 (file)
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -158,6 +158,7 @@ ENTRY(_ex_single_step)
        cc = r7 == r6;
        if cc jump _bfin_return_from_exception;
 
+#ifdef CONFIG_KGDB
        /* Don't do single step in hardware exception handler */
         p5.l = lo(IPEND);
         p5.h = hi(IPEND);
@@ -165,7 +166,6 @@ ENTRY(_ex_single_step)
        cc = bittst(r6, 5);
        if cc jump _bfin_return_from_exception;
 
-#ifdef CONFIG_KGDB
        /* skip single step if current interrupt priority is higher than
         * that of the first instruction, from which gdb starts single step */
        r6 >>= 6;
@@ -191,12 +191,22 @@ ENTRY(_ex_single_step)
 #endif
 
        /* If we were in user mode, do the single step normally.  */
+       p5.l = lo(IPEND);
+       p5.h = hi(IPEND);
        r6 = [p5];
        r7 = 0xffe0 (z);
        r7 = r7 & r6;
        cc = r7 == 0;
-       if cc jump 1f;
+       if !cc jump 1f;
 
+       /* Single stepping only a single instruction, so clear the trace
+        * bit here.  */
+       r7 = syscfg;
+       bitclr (r7, 0);
+       syscfg = R7;
+       jump _ex_trap_c;
+
+1:
        /*
         * We were in an interrupt handler.  By convention, all of them save
         * SYSCFG with their first instruction, so by checking whether our
@@ -224,15 +234,11 @@ ENTRY(_ex_single_step)
        cc = R7 == R6;
        if !cc jump _bfin_return_from_exception;
 
-1:
-       /* Single stepping only a single instruction, so clear the trace
-        * bit here.  */
        r7 = syscfg;
        bitclr (r7, 0);
        syscfg = R7;
 
-       jump _ex_trap_c;
-
+       /* Fall through to _bfin_return_from_exception.  */
 ENDPROC(_ex_single_step)
 
 ENTRY(_bfin_return_from_exception)