[Blackfin] arch: fix gdb testing regression
When transferring to IRQ5 from an exception, save SYSCFG in memory across the
transfer and clear the trace bit.
When we get a single step exception, check whether we can safely clear the
trace bit in SYSCFG. We can (and should) clear it after the first instruction
of the interrupt handler; the first insn saves SYSCFG to the stack in all
handlers.
Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
diff --git a/include/asm-blackfin/mach-common/context.S b/include/asm-blackfin/mach-common/context.S
index fd0ebe1..c0e630e 100644
--- a/include/asm-blackfin/mach-common/context.S
+++ b/include/asm-blackfin/mach-common/context.S
@@ -28,6 +28,11 @@
*/
/*
+ * NOTE! The single-stepping code assumes that all interrupt handlers
+ * start by saving SYSCFG on the stack with their first instruction.
+ */
+
+/*
* Code to save processor context.
* We even save the register which are preserved by a function call
* - r4, r5, r6, r7, p3, p4, p5