stlink: fix stlink api2 single step

This makes the newer v2 api behave as per the v1 api, eg. single stepping
masks all interrupts.

A better long term solution is to use same behaviour as a cortex-m3
target, see CORTEX_M3_ISRMASK_AUTO.

Change-Id: Iaf9f9adf225cf274faaac938050bb996582aa98f
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/621
Tested-by: jenkins

diff --git a/src/jtag/drivers/stlink_usb.c b/src/jtag/drivers/stlink_usb.c
index b4944f56cd77e98ce3d125de7745bc6ab8a54c32..708b24b41c8fc00056453dc42dc5e6209b1e1847 100644 (file)
--- a/src/jtag/drivers/stlink_usb.c
+++ b/src/jtag/drivers/stlink_usb.c
@@ -872,8 +872,13 @@ static int stlink_usb_step(void *handle)
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       if (h->jtag_api == STLINK_JTAG_API_V2)
-               return stlink_usb_write_debug_reg(handle, DCB_DHCSR, DBGKEY|C_STEP|C_DEBUGEN);
+       if (h->jtag_api == STLINK_JTAG_API_V2) {
+               /* TODO: this emulates the v1 api, it should really use a similar auto mask isr
+                * that the cortex-m3 currently does. */
+               stlink_usb_write_debug_reg(handle, DCB_DHCSR, DBGKEY|C_HALT|C_MASKINTS|C_DEBUGEN);
+               stlink_usb_write_debug_reg(handle, DCB_DHCSR, DBGKEY|C_STEP|C_MASKINTS|C_DEBUGEN);
+               return stlink_usb_write_debug_reg(handle, DCB_DHCSR, DBGKEY|C_HALT|C_DEBUGEN);
+       }
 
        stlink_usb_init_buffer(handle, STLINK_RX_EP, 2);