platform/chrome: cros_ec_proto: avoid -Wflex-array-member-not-at-end warnings

Use the `DEFINE_RAW_FLEX()` helper for an on-stack definition of
a flexible structure where the size of the flexible-array member
is known at compile-time, and refactor the rest of the code,
accordingly.

So, with these changes, fix the following warning:
drivers/platform/chrome/cros_ec_proto_test.c:1547:40: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
drivers/platform/chrome/cros_ec_proto_test.c:1607:40: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
drivers/platform/chrome/cros_ec_proto_test.c:1645:40: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
drivers/platform/chrome/cros_ec_proto_test.c:1668:40: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]

Link: KSPP/linux#202
Signed-off-by: Gustavo A. R. Silva <[email protected]>
Link: https://lore.kernel.org/r/ZgMaDl/of8YC445S@neat
Signed-off-by: Tzung-Bi Shih <[email protected]>

Author: GustavoARSilva

drivers/platform/chrome/cros_ec_proto_test.c

@@ -1543,21 +1543,18 @@ static void cros_ec_proto_test_cmd_xfer_normal(struct kunit *test)
 	struct cros_ec_device *ec_dev = &priv->ec_dev;
 	struct ec_xfer_mock *mock;
 	int ret;
-	struct {
-		struct cros_ec_command msg;
-		u8 data[0x100];
-	} __packed buf;
+	DEFINE_RAW_FLEX(struct cros_ec_command, buf, data, 0x100);
 
 	ec_dev->max_request = 0xff;
 	ec_dev->max_response = 0xee;
 	ec_dev->max_passthru = 0xdd;
 
-	buf.msg.version = 0;
-	buf.msg.command = EC_CMD_HELLO;
-	buf.msg.insize = 4;
-	buf.msg.outsize = 2;
-	buf.data[0] = 0x55;
-	buf.data[1] = 0xaa;
+	buf->version = 0;
+	buf->command = EC_CMD_HELLO;
+	buf->insize = 4;
+	buf->outsize = 2;
+	buf->data[0] = 0x55;
+	buf->data[1] = 0xaa;
 
 	{
 		u8 *data;
@@ -1572,7 +1569,7 @@ static void cros_ec_proto_test_cmd_xfer_normal(struct kunit *test)
 		data[3] = 0x33;
 	}
 
-	ret = cros_ec_cmd_xfer(ec_dev, &buf.msg);
+	ret = cros_ec_cmd_xfer(ec_dev, buf);
 	KUNIT_EXPECT_EQ(test, ret, 4);
 
 	{
@@ -1590,10 +1587,10 @@ static void cros_ec_proto_test_cmd_xfer_normal(struct kunit *test)
 		KUNIT_EXPECT_EQ(test, data[0], 0x55);
 		KUNIT_EXPECT_EQ(test, data[1], 0xaa);
 
-		KUNIT_EXPECT_EQ(test, buf.data[0], 0xaa);
-		KUNIT_EXPECT_EQ(test, buf.data[1], 0x55);
-		KUNIT_EXPECT_EQ(test, buf.data[2], 0xcc);
-		KUNIT_EXPECT_EQ(test, buf.data[3], 0x33);
+		KUNIT_EXPECT_EQ(test, buf->data[0], 0xaa);
+		KUNIT_EXPECT_EQ(test, buf->data[1], 0x55);
+		KUNIT_EXPECT_EQ(test, buf->data[2], 0xcc);
+		KUNIT_EXPECT_EQ(test, buf->data[3], 0x33);
 	}
 }
 
@@ -1603,26 +1600,23 @@ static void cros_ec_proto_test_cmd_xfer_excess_msg_insize(struct kunit *test)
 	struct cros_ec_device *ec_dev = &priv->ec_dev;
 	struct ec_xfer_mock *mock;
 	int ret;
-	struct {
-		struct cros_ec_command msg;
-		u8 data[0x100];
-	} __packed buf;
+	DEFINE_RAW_FLEX(struct cros_ec_command, buf, data, 0x100);
 
 	ec_dev->max_request = 0xff;
 	ec_dev->max_response = 0xee;
 	ec_dev->max_passthru = 0xdd;
 
-	buf.msg.version = 0;
-	buf.msg.command = EC_CMD_HELLO;
-	buf.msg.insize = 0xee + 1;
-	buf.msg.outsize = 2;
+	buf->version = 0;
+	buf->command = EC_CMD_HELLO;
+	buf->insize = 0xee + 1;
+	buf->outsize = 2;
 
 	{
 		mock = cros_kunit_ec_xfer_mock_add(test, 0xcc);
 		KUNIT_ASSERT_PTR_NE(test, mock, NULL);
 	}
 
-	ret = cros_ec_cmd_xfer(ec_dev, &buf.msg);
+	ret = cros_ec_cmd_xfer(ec_dev, buf);
 	KUNIT_EXPECT_EQ(test, ret, 0xcc);
 
 	{
@@ -1641,21 +1635,18 @@ static void cros_ec_proto_test_cmd_xfer_excess_msg_outsize_without_passthru(stru
 	struct cros_ec_proto_test_priv *priv = test->priv;
 	struct cros_ec_device *ec_dev = &priv->ec_dev;
 	int ret;
-	struct {
-		struct cros_ec_command msg;
-		u8 data[0x100];
-	} __packed buf;
+	DEFINE_RAW_FLEX(struct cros_ec_command, buf, data, 0x100);
 
 	ec_dev->max_request = 0xff;
 	ec_dev->max_response = 0xee;
 	ec_dev->max_passthru = 0xdd;
 
-	buf.msg.version = 0;
-	buf.msg.command = EC_CMD_HELLO;
-	buf.msg.insize = 4;
-	buf.msg.outsize = 0xff + 1;
+	buf->version = 0;
+	buf->command = EC_CMD_HELLO;
+	buf->insize = 4;
+	buf->outsize = 0xff + 1;
 
-	ret = cros_ec_cmd_xfer(ec_dev, &buf.msg);
+	ret = cros_ec_cmd_xfer(ec_dev, buf);
 	KUNIT_EXPECT_EQ(test, ret, -EMSGSIZE);
 }
 
@@ -1664,21 +1655,18 @@ static void cros_ec_proto_test_cmd_xfer_excess_msg_outsize_with_passthru(struct
 	struct cros_ec_proto_test_priv *priv = test->priv;
 	struct cros_ec_device *ec_dev = &priv->ec_dev;
 	int ret;
-	struct {
-		struct cros_ec_command msg;
-		u8 data[0x100];
-	} __packed buf;
+	DEFINE_RAW_FLEX(struct cros_ec_command, buf, data, 0x100);
 
 	ec_dev->max_request = 0xff;
 	ec_dev->max_response = 0xee;
 	ec_dev->max_passthru = 0xdd;
 
-	buf.msg.version = 0;
-	buf.msg.command = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX) + EC_CMD_HELLO;
-	buf.msg.insize = 4;
-	buf.msg.outsize = 0xdd + 1;
+	buf->version = 0;
+	buf->command = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX) + EC_CMD_HELLO;
+	buf->insize = 4;
+	buf->outsize = 0xdd + 1;
 
-	ret = cros_ec_cmd_xfer(ec_dev, &buf.msg);
+	ret = cros_ec_cmd_xfer(ec_dev, buf);
 	KUNIT_EXPECT_EQ(test, ret, -EMSGSIZE);
 }