Messages in this thread | | | From | Tzung-Bi Shih <> | Subject | [PATCH v2 00/10] platform/chrome: Kunit tests and refactor for cros_ec_cmd_xfer() | Date | Mon, 18 Jul 2022 05:09:04 +0000 |
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The 1st patch fixes an issue that cros_kunit_ec_xfer_mock() could return garbage bytes for `msg->result` if the mock list is empty.
The 2nd ~ 6th patches add Kunit tests and refactors for cros_ec_cmd_xfer().
The last 4 patches change the behavior a bit by altering return codes.
Asynchronous mechanism in EC protocol: EC returns EC_RES_IN_PROGRESS if the host command needs more time to complete. It saves the result into `saved_result` once the command completed[1].
By design, AP should send another command EC_CMD_RESEND_RESPONSE for getting the result from the previous pending command[2]. The mechanism was only designed for commands that don't need responses[3].
However, the kernel code doesn't have such logic when dealing with EC_RES_IN_PROGRESS.
The series doesn't fix it but leave it as is. I doubt there is no existing use case.
[1]: https://crrev.com/9b80051e01872d8cae86fff999b5d31a0bea985b/common/host_command.c#113 [2]: https://crrev.com/9b80051e01872d8cae86fff999b5d31a0bea985b/common/host_command.c#748 [3]: https://crrev.com/9b80051e01872d8cae86fff999b5d31a0bea985b/common/host_command.c#126
Return value overridden in cros_ec_send_command() if asynchronous: By original intention, cros_ec_send_command() returns number of available bytes of input payload.
When it falls into asynchronous path (i.e. EC_RES_IN_PROGRESS), both return value and `msg->result` will be overridden by the subsequent EC_CMD_GET_COMMS_STATUS.
The series doesn't fix it but leave it as is.
Tzung-Bi Shih (10): platform/chrome: cros_kunit_util: add default value for `msg->result` platform/chrome: cros_ec_proto: add "cros_ec_" prefix to send_command() platform/chrome: cros_ec_proto: add Kunit tests for cros_ec_cmd_xfer() platform/chrome: cros_ec_proto: add Kunit tests for cros_ec_send_command() platform/chrome: cros_ec_proto: separate cros_ec_xfer_command() platform/chrome: cros_ec_proto: separate cros_ec_wait_until_complete() platform/chrome: cros_ec_proto: change Kunit expectation when timed out platform/chrome: cros_ec_proto: return -EAGAIN when retries timed out platform/chrome: cros_ec_proto: add Kunit test for empty payload platform/chrome: cros_ec_proto: return -EPROTO if empty payload
drivers/platform/chrome/cros_ec_proto.c | 102 +++-- drivers/platform/chrome/cros_ec_proto_test.c | 443 +++++++++++++++++++ drivers/platform/chrome/cros_kunit_util.c | 27 +- drivers/platform/chrome/cros_kunit_util.h | 5 + 4 files changed, 530 insertions(+), 47 deletions(-)
Changes from v1 (https://patchwork.kernel.org/project/chrome-platform/cover/20220628024913.1755292-1-tzungbi@kernel.org/): - Drop "platform/chrome: cros_ec_proto: change Kunit expectation for EC errors" and "platform/chrome: cros_ec_proto: return standard error codes for EC errors" because they could break existing ABI. - Add "platform/chrome: cros_kunit_util: add default value for `msg->result`".
-- 2.37.0.170.g444d1eabd0-goog
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