Re: [PATCH 11/13] platform/chrome: cros_ec_proto: fix get_host_command_version_mask() returns
From: Guenter Roeck
Date: Mon Jun 06 2022 - 12:17:12 EST
On Mon, Jun 6, 2022 at 7:12 AM Tzung-Bi Shih <tzungbi@xxxxxxxxxx> wrote:
>
> `mask` of get_host_command_version_mask() is valid only if it returns
> positive number (i.e. sizeof(struct ec_response_get_cmd_versions)).
>
> - Remove the unneeded `ver_mask` initialization.
>
> - Update callers of get_host_command_version_mask() for checking correct
> return values.
>
I think it would be better to have the function return a negative
error value instead of 0 if returning 0 is indeed an error. I also
wonder if the caller ever uses a return value > 0, or if the function
should just return 0 if there was no error.
Thanks,
Guenter
> - Add a Kunit test: `ver_mask` has some garbage bytes from
> previous EC_CMD_GET_NEXT_EVENT but there is no host sleep.
>
> Signed-off-by: Tzung-Bi Shih <tzungbi@xxxxxxxxxx>
> ---
> drivers/platform/chrome/cros_ec_proto.c | 8 +-
> drivers/platform/chrome/cros_ec_proto_test.c | 109 +++++++++++++++++++
> 2 files changed, 113 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index 07b57ea105b6..91c945c9911f 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -409,7 +409,7 @@ static int fill_protocol_info_legacy(struct cros_ec_device *ec_dev)
> * @cmd: command to get the version of.
> * @mask: result when function returns 0.
> *
> - * @return 0 on success, error code otherwise
> + * @return >0 on success, error code otherwise
> *
> * LOCKING:
> * the caller has ec_dev->lock mutex or the caller knows there is
> @@ -454,7 +454,7 @@ static int get_host_command_version_mask(struct cros_ec_device *ec_dev, u16 cmd,
> int cros_ec_query_all(struct cros_ec_device *ec_dev)
> {
> struct device *dev = ec_dev->dev;
> - u32 ver_mask = 0;
> + u32 ver_mask;
> int ret;
>
> /* First try sending with proto v3. */
> @@ -486,7 +486,7 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
>
> /* Probe if MKBP event is supported */
> ret = get_host_command_version_mask(ec_dev, EC_CMD_GET_NEXT_EVENT, &ver_mask);
> - if (ret < 0 || ver_mask == 0) {
> + if (ret <= 0 || ver_mask == 0) {
> ec_dev->mkbp_event_supported = 0;
> } else {
> ec_dev->mkbp_event_supported = fls(ver_mask);
> @@ -495,7 +495,7 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
>
> /* Probe if host sleep v1 is supported for S0ix failure detection. */
> ret = get_host_command_version_mask(ec_dev, EC_CMD_HOST_SLEEP_EVENT, &ver_mask);
> - ec_dev->host_sleep_v1 = (ret >= 0 && (ver_mask & EC_VER_MASK(1)));
> + ec_dev->host_sleep_v1 = (ret > 0 && (ver_mask & EC_VER_MASK(1)));
>
> /* Get host event wake mask. */
> ret = cros_ec_get_host_event_wake_mask(ec_dev, &ec_dev->host_event_wake_mask);
> diff --git a/drivers/platform/chrome/cros_ec_proto_test.c b/drivers/platform/chrome/cros_ec_proto_test.c
> index e2c369765612..7d73aeb99d1d 100644
> --- a/drivers/platform/chrome/cros_ec_proto_test.c
> +++ b/drivers/platform/chrome/cros_ec_proto_test.c
> @@ -760,6 +760,114 @@ static void cros_ec_proto_test_query_all_no_host_sleep(struct kunit *test)
> }
> }
>
> +static void cros_ec_proto_test_query_all_no_host_sleep2(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_sleep_v1 = true;
> +
> + /* 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. */
> + {
> + struct ec_response_get_cmd_versions *data;
> +
> + mock = cros_kunit_ec_xfer_mock_add(test, sizeof(*data));
> + KUNIT_ASSERT_PTR_NE(test, mock, NULL);
> +
> + /* In order to pollute next get_host_command_version_mask(). */
> + data = (struct ec_response_get_cmd_versions *)mock->o_data;
> + data->version_mask = 0xbeef;
> + }
> +
> + /* For get_host_command_version_mask() for host sleep v1. */
> + {
> + 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));
> +
> + KUNIT_EXPECT_FALSE(test, ec_dev->host_sleep_v1);
> + }
> +}
> +
> static void cros_ec_proto_test_query_all_default_wake_mask(struct kunit *test)
> {
> struct cros_ec_proto_test_priv *priv = test->priv;
> @@ -941,6 +1049,7 @@ static struct kunit_case cros_ec_proto_test_cases[] = {
> KUNIT_CASE(cros_ec_proto_test_query_all_no_mkbp),
> KUNIT_CASE(cros_ec_proto_test_query_all_no_mkbp2),
> 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),
> {}
> };
> --
> 2.36.1.255.ge46751e96f-goog
>