Re: [PATCH 13/13] platform/chrome: cros_ec_proto: fix get_host_event_wake_mask() returns

From: Guenter Roeck
Date: Mon Jun 06 2022 - 12:14:45 EST

On Mon, Jun 6, 2022 at 7:12 AM Tzung-Bi Shih <tzungbi@xxxxxxxxxx> wrote:
>
> get_host_event_wake_mask() only gets valid result if send_command()
> returns sizeof(struct ec_response_host_event_mask). Simplify the
> code and correct the callers.
>
> Also add a Kunit test for guarding if get_host_event_wake_mask() returns 0.
>
> Signed-off-by: Tzung-Bi Shih <tzungbi@xxxxxxxxxx>
> ---
> drivers/platform/chrome/cros_ec_proto.c | 15 +--
> drivers/platform/chrome/cros_ec_proto_test.c | 131 +++++++++++++++++++
> 2 files changed, 137 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index 1622e24747c9..1d2399473f35 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -236,7 +236,7 @@ EXPORT_SYMBOL(cros_ec_check_result);
> *
> * @ec_dev: EC device to call
> * @msg: message structure to use
> - * @mask: result when function returns >=0.
> + * @mask: result when function returns >0.
> *
> * LOCKING:
> * the caller has ec_dev->lock mutex, or the caller knows there is
> @@ -256,19 +256,16 @@ static int get_host_event_wake_mask(struct cros_ec_device *ec_dev, uint32_t *mas
> msg->insize = sizeof(*r);
>
> ret = send_command(ec_dev, msg);
> - if (ret >= 0) {
> + if (ret > 0) {

The idea here was to (potentially) return an error if ret == 0. This
is no longer the case after this change. Instead, the caller has to
check for ret == 0 and treat it as an error. I think it would make
more sense to explicitly check for ret ==0, eg with something like

mapped = cros_ec_map_error(msg->result);
if (mapped) {
ret = mapped;
goto exit;
}
if (ret == 0) {
ret = -EPROTO;
goto exit;
}
....

> mapped = cros_ec_map_error(msg->result);
> if (mapped) {
> ret = mapped;
> - goto exit;
> + } else {
> + r = (struct ec_response_host_event_mask *)msg->data;
> + *mask = r->mask;
> }
> }
> - if (ret > 0) {
> - r = (struct ec_response_host_event_mask *)msg->data;
> - *mask = r->mask;
> - }
>
> -exit:
> kfree(msg);
> return ret;
> }
> @@ -499,7 +496,7 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
>
> /* Get host event wake mask. */
> ret = get_host_event_wake_mask(ec_dev, &ec_dev->host_event_wake_mask);
> - if (ret < 0) {
> + if (ret <= 0) {
> /*
> * If the EC doesn't support EC_CMD_HOST_EVENT_GET_WAKE_MASK,
> * use a reasonable default. Note that we ignore various
> diff --git a/drivers/platform/chrome/cros_ec_proto_test.c b/drivers/platform/chrome/cros_ec_proto_test.c
> index f63196289f54..1ccc837b30cf 100644
> --- a/drivers/platform/chrome/cros_ec_proto_test.c
> +++ b/drivers/platform/chrome/cros_ec_proto_test.c
> @@ -999,6 +999,136 @@ static void cros_ec_proto_test_query_all_default_wake_mask(struct kunit *test)
> }
> }
>
> +static void cros_ec_proto_test_query_all_default_wake_mask2(struct kunit *test)
> +{
> + struct cros_ec_proto_test_priv *priv = test->priv;
> + struct cros_ec_device *ec_dev = &priv->ec_dev;
> + struct ec_xfer_mock *mock;
> + int ret;
> +
> + /* Set some garbage bytes. */
> + ec_dev->host_event_wake_mask = U32_MAX;
> +
> + /* For fill_protocol_info() without passthru. */
> + {
> + struct ec_response_get_protocol_info *data;
> +
> + mock = cros_kunit_ec_xfer_mock_add(test, sizeof(*data));
> + KUNIT_ASSERT_PTR_NE(test, mock, NULL);
> +
> + /*
> + * Although it doesn't check the value, provides valid sizes so that
> + * cros_ec_query_all() allocates din and dout correctly.
> + */
> + data = (struct ec_response_get_protocol_info *)mock->o_data;
> + data->max_request_packet_size = 0xbe;
> + data->max_response_packet_size = 0xef;
> + }
> +
> + /* For fill_protocol_info() with passthru. */
> + {
> + mock = cros_kunit_ec_xfer_mock_addx(test, 0, EC_RES_INVALID_COMMAND,
> + sizeof(struct ec_response_get_protocol_info));
> + KUNIT_ASSERT_PTR_NE(test, mock, NULL);
> + }
> +
> + /* For get_host_command_version_mask() for MKBP. */
> + {
> + mock = cros_kunit_ec_xfer_mock_add(test,
> + sizeof(struct ec_response_get_cmd_versions));
> + KUNIT_ASSERT_PTR_NE(test, mock, NULL);
> + }
> +
> + /* For get_host_command_version_mask() for host sleep v1. */
> + {
> + mock = cros_kunit_ec_xfer_mock_add(test,
> + sizeof(struct ec_response_get_cmd_versions));
> + KUNIT_ASSERT_PTR_NE(test, mock, NULL);
> + }
> +
> + /* For get_host_event_wake_mask(). */
> + {
> + mock = cros_kunit_ec_xfer_mock_add(test, 0);
> + KUNIT_ASSERT_PTR_NE(test, mock, NULL);
> + }
> +
> + cros_ec_proto_test_query_all_pretest(test);
> + ret = cros_ec_query_all(ec_dev);
> + KUNIT_EXPECT_EQ(test, ret, 0);
> +
> + /* For fill_protocol_info() without passthru. */
> + {
> + mock = cros_kunit_ec_xfer_mock_next();
> + KUNIT_EXPECT_PTR_NE(test, mock, NULL);
> +
> + KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
> + KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_GET_PROTOCOL_INFO);
> + KUNIT_EXPECT_EQ(test, mock->msg.insize,
> + sizeof(struct ec_response_get_protocol_info));
> + KUNIT_EXPECT_EQ(test, mock->msg.outsize, 0);
> + }
> +
> + /* For fill_protocol_info() with passthru. */
> + {
> + mock = cros_kunit_ec_xfer_mock_next();
> + KUNIT_EXPECT_PTR_NE(test, mock, NULL);
> +
> + KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
> + KUNIT_EXPECT_EQ(test, mock->msg.command,
> + EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX) |
> + EC_CMD_GET_PROTOCOL_INFO);
> + KUNIT_EXPECT_EQ(test, mock->msg.insize,
> + sizeof(struct ec_response_get_protocol_info));
> + KUNIT_EXPECT_EQ(test, mock->msg.outsize, 0);
> + }
> +
> + /* For get_host_command_version_mask() for MKBP. */
> + {
> + mock = cros_kunit_ec_xfer_mock_next();
> + KUNIT_EXPECT_PTR_NE(test, mock, NULL);
> +
> + KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
> + KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_GET_CMD_VERSIONS);
> + KUNIT_EXPECT_EQ(test, mock->msg.insize,
> + sizeof(struct ec_response_get_cmd_versions));
> + KUNIT_EXPECT_EQ(test, mock->msg.outsize, sizeof(struct ec_params_get_cmd_versions));
> + }
> +
> + /* For get_host_command_version_mask() for host sleep v1. */
> + {
> + mock = cros_kunit_ec_xfer_mock_next();
> + KUNIT_EXPECT_PTR_NE(test, mock, NULL);
> +
> + KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
> + KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_GET_CMD_VERSIONS);
> + KUNIT_EXPECT_EQ(test, mock->msg.insize,
> + sizeof(struct ec_response_get_cmd_versions));
> + KUNIT_EXPECT_EQ(test, mock->msg.outsize, sizeof(struct ec_params_get_cmd_versions));
> + }
> +
> + /* For get_host_event_wake_mask(). */
> + {
> + u32 mask;
> +
> + mock = cros_kunit_ec_xfer_mock_next();
> + KUNIT_EXPECT_PTR_NE(test, mock, NULL);
> +
> + KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
> + KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_HOST_EVENT_GET_WAKE_MASK);
> + KUNIT_EXPECT_EQ(test, mock->msg.insize, sizeof(struct ec_response_host_event_mask));
> + KUNIT_EXPECT_EQ(test, mock->msg.outsize, 0);
> +
> + mask = ec_dev->host_event_wake_mask;
> + KUNIT_EXPECT_EQ(test, mask & EC_HOST_EVENT_MASK(EC_HOST_EVENT_LID_CLOSED), 0);
> + KUNIT_EXPECT_EQ(test, mask & EC_HOST_EVENT_MASK(EC_HOST_EVENT_AC_DISCONNECTED), 0);
> + KUNIT_EXPECT_EQ(test, mask & EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_LOW), 0);
> + KUNIT_EXPECT_EQ(test, mask & EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_CRITICAL), 0);
> + KUNIT_EXPECT_EQ(test, mask & EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY), 0);
> + KUNIT_EXPECT_EQ(test, mask & EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU), 0);
> + KUNIT_EXPECT_EQ(test, mask & EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_STATUS), 0);
> + }
> +}
> +
> static int cros_ec_proto_test_init(struct kunit *test)
> {
> struct cros_ec_proto_test_priv *priv;
> @@ -1051,6 +1181,7 @@ static struct kunit_case cros_ec_proto_test_cases[] = {
> KUNIT_CASE(cros_ec_proto_test_query_all_no_host_sleep),
> KUNIT_CASE(cros_ec_proto_test_query_all_no_host_sleep2),
> KUNIT_CASE(cros_ec_proto_test_query_all_default_wake_mask),
> + KUNIT_CASE(cros_ec_proto_test_query_all_default_wake_mask2),
> {}
> };
>
> --
> 2.36.1.255.ge46751e96f-goog
>