[cmis] Fix enter_password to include standard password entry method#724
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Junchao-Mellanox wants to merge 2 commits into
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[cmis] Fix enter_password to include standard password entry method#724Junchao-Mellanox wants to merge 2 commits into
Junchao-Mellanox wants to merge 2 commits into
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#### Why I did it `CdbCmdHandler.enter_password()` previously delivered the CMIS host password only via CDB command `0001h`. This is not the standard mechanism defined by the CMIS spec and is not honored by all modules — the standard, universally-supported way to unlock password-protected CDB/EEPROM access is to write the 4-byte host password (MSB first) to the Password Entry Area at page 00h bytes 122-125. As a result, password entry would fail on modules that only unlock via the Password Entry Area, blocking protected CDB/EEPROM operations (e.g. firmware/SED-protected access) on those modules. #### How I did it - `cdb.py` — Reworked `enter_password()` to first write the password to the Password Entry Area (page 00h bytes 122-125, MSB first) using `write_raw`, which is the standard method honored by all CMIS modules. If that write fails, it falls back to the original CDB command `0001h` path for modules that rely on it. Input validation (integer in range `0..0xFFFFFFFF`) is preserved, and `struct` is used to pack the 32-bit password big-endian. - `cdb_consts.py` — Added `CDB_HOST_PASSWORD_ENTRY_OFFSET = 122` and `CDB_HOST_PASSWORD_ENTRY_SIZE = 4` with documentation describing the Password Entry Area register layout. - `test_cdb.py` — Updated existing tests to assert the password is now written MSB-first to the Password Entry Area (and that no CDB command is sent when the register write succeeds), and added `test_enter_password_fallback_to_cdb_command` to cover the fallback path when the register write fails. #### How to verify it Ran the updated unit tests in `tests/sonic_xcvr/test_cdb.py`, covering: - `test_enter_password_valid` — password written MSB-first to the Password Entry Area, no CDB command issued. - `test_enter_password_default` — default password (`0x00001011`) written to the Password Entry Area. - `test_enter_password_fallback_to_cdb_command` — CDB command `0001h` used as fallback when the register write returns `False`. Signed-off-by: Junchao Chen <junchao@mellanox.com>
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Hi @prgeor , @mihirpat1 , could you please help review this? Thanks! |
stephenxs
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Jul 21, 2026
Signed-off-by: Junchao Chen <junchao@mellanox.com>
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Why I did it
CdbCmdHandler.enter_password()previously delivered the CMIS host password only via CDB command0001h. This is not the standard mechanism defined by the CMIS spec and is not honored by all modules — the standard, universally-supported way to unlock password-protected CDB/EEPROM access is to write the 4-byte host password (MSB first) to the Password Entry Area at page 00h bytes 122-125. As a result, password entry would fail on modules that only unlock via the Password Entry Area, blocking protected CDB/EEPROM operations (e.g. firmware/SED-protected access) on those modules.How I did it
cdb.py— Reworkedenter_password()to first write the password to the Password Entry Area (page 00h bytes 122-125, MSB first) usingwrite_raw, which is the standard method honored by all CMIS modules. If that write fails, it falls back to the original CDB command0001hpath for modules that rely on it. Input validation (integer in range0..0xFFFFFFFF) is preserved, andstructis used to pack the 32-bit password big-endian.cdb_consts.py— AddedCDB_HOST_PASSWORD_ENTRY_OFFSET = 122andCDB_HOST_PASSWORD_ENTRY_SIZE = 4with documentation describing the Password Entry Area register layout.test_cdb.py— Updated existing tests to assert the password is now written MSB-first to the Password Entry Area (and that no CDB command is sent when the register write succeeds), and addedtest_enter_password_fallback_to_cdb_commandto cover the fallback path when the register write fails.How to verify it
Ran the updated unit tests in
tests/sonic_xcvr/test_cdb.py, covering:test_enter_password_valid— password written MSB-first to the Password Entry Area, no CDB command issued.test_enter_password_default— default password (0x00001011) written to the Password Entry Area.test_enter_password_fallback_to_cdb_command— CDB command0001hused as fallback when the register write returnsFalse.