From: Øyvind Harboe <oyvind.harboe@zylin.com>
Date: Wed, 13 Apr 2011 19:51:42 +0000 (+0200)
Subject: jtag: clarify jtag->init() and jtag->quit() definitions
X-Git-Tag: v0.5.0-rc1~87
X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=e984dc1f162ab2bd94629c32d640d804b0295553;p=openocd

jtag: clarify jtag->init() and jtag->quit() definitions

only set jtag global pointer if jtag->init() succeeds. Less code,
more clear what the rules are.

Fix nit that error value from init() was not propagated unmodified.

Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>
---

diff --git a/src/jtag/core.c b/src/jtag/core.c
index 68c12570..4c5d37a7 100644
--- a/src/jtag/core.c
+++ b/src/jtag/core.c
@@ -1368,12 +1368,13 @@ int adapter_init(struct command_context *cmd_ctx)
 		return ERROR_JTAG_INVALID_INTERFACE;
 	}
 
-	jtag = jtag_interface;
-	if (jtag_interface->init() != ERROR_OK)
+	int retval;
+	retval = jtag_interface->init();
+	if (retval != ERROR_OK)
 	{
-		jtag = NULL;
-		return ERROR_JTAG_INIT_FAILED;
+		return retval;
 	}
+	jtag = jtag_interface;
 
 	/* LEGACY SUPPORT ... adapter drivers  must declare what
 	 * transports they allow.  Until they all do so, assume
@@ -1383,7 +1384,7 @@ int adapter_init(struct command_context *cmd_ctx)
 		LOG_ERROR("Adapter driver '%s' did not declare "
 			"which transports it allows; assuming "
 			"JTAG-only", jtag->name);
-		int retval = allow_transports(cmd_ctx, jtag_only);
+		retval = allow_transports(cmd_ctx, jtag_only);
 		if (retval != ERROR_OK)
 			return retval;
 	}
@@ -1391,7 +1392,7 @@ int adapter_init(struct command_context *cmd_ctx)
 	int requested_khz = jtag_get_speed_khz();
 	int actual_khz = requested_khz;
 	int jtag_speed_var;
-	int retval = jtag_get_speed(&jtag_speed_var);
+	retval = jtag_get_speed(&jtag_speed_var);
 	if (retval != ERROR_OK)
 		return retval;
 	retval = jtag_get_speed_readable(&actual_khz);
diff --git a/src/jtag/interface.h b/src/jtag/interface.h
index 958af8f5..1059436e 100644
--- a/src/jtag/interface.h
+++ b/src/jtag/interface.h
@@ -231,8 +231,14 @@ struct jtag_interface {
 	const struct command_registration *commands;
 
 	/**
-	 * Interface driver must initalize any resources and connect to a
+	 * Interface driver must initialize any resources and connect to a
 	 * JTAG device.
+	 *
+	 * quit() is invoked if and only if init() succeeds. quit() is always
+	 * invoked if init() succeeds. Same as malloc() + free(). Always
+	 * invoke free() if malloc() succeeds and do not invoke free()
+	 * otherwise.
+	 *
 	 * @returns ERROR_OK on success, or an error code on failure.
 	 */
 	int (*init)(void);
@@ -240,6 +246,7 @@ struct jtag_interface {
 	/**
 	 * Interface driver must tear down all resources and disconnect from
 	 * the JTAG device.
+	 *
 	 * @returns ERROR_OK on success, or an error code on failure.
 	 */
 	int (*quit)(void);