From: Hans Verkuil <hans.verkuil@xxxxxxxxx> This patch series adds support for CEC error injection for drivers using the CEC Pin Framework (cec-pin.c). There are two CEC drivers currently using this framework: the sun4i Allwinner A10/A20 driver and the cec-gpio driver. This patch series was developed with the cec-gpio driver and a Raspberry Pi. The CEC Pin Framework is meant for hardware that has no high-level support but only direct low-level control of the bus (i.e. pull the CEC line down or read the CEC line). Low-level bus access like that is ideal to implement error injection since you have full control of the bus and you can do anything you want. This new error injection framework can create most if not all error conditions that I could think of. We (Cisco) used it to verify our own CEC implementation and in fact this error injection framework was developed together with the low-level CEC analysis code in the cec-ctl userspace utility to analyze what is happening on the bus. I have been working on creating scripts that can test a remote CEC adapter for low-level compliance with the CEC standard: https://git.linuxtv.org/hverkuil/v4l-utils.git/log/?h=cec-pin-tests (note: these scripts are for the v1 version of this patch series, they need to be updated for this v2) These scripts are not complete yet since it isn't smart enough to tell the difference between different (but valid) interpretations of the CEC specification and actual violations of the specification. I plan to continue working on that since I would like to have a test-suite that can check a CEC implementation automatically. Special thanks go to Wolfram Sang since his i2c error injection presentation at the Embedded Linux Conference Europe 2017 inspired me to switch to debugfs for this instead of using ioctls. Changes since v1: - added 'mode' support (off/once/always/toggle). - simplified the error injection data structures and logic. - added patch 7 to log various errors in the 'status' debugfs file. Regards, Hans Hans Verkuil (7): cec: add core error injection support cec-core.rst: document the error injection ops cec-pin: create cec_pin_start_timer() function cec-pin-error-inj: parse/show error injection cec-pin: add error injection support cec-pin-error-inj.rst: document CEC Pin Error Injection cec-pin: improve status log .../media/cec-drivers/cec-pin-error-inj.rst | 322 +++++++++++ Documentation/media/cec-drivers/index.rst | 1 + Documentation/media/kapi/cec-core.rst | 72 ++- MAINTAINERS | 1 + drivers/media/cec/Kconfig | 6 + drivers/media/cec/Makefile | 4 + drivers/media/cec/cec-core.c | 58 ++ drivers/media/cec/cec-pin-error-inj.c | 341 +++++++++++ drivers/media/cec/cec-pin-priv.h | 124 +++- drivers/media/cec/cec-pin.c | 627 ++++++++++++++++++--- include/media/cec.h | 5 + 11 files changed, 1490 insertions(+), 71 deletions(-) create mode 100644 Documentation/media/cec-drivers/cec-pin-error-inj.rst create mode 100644 drivers/media/cec/cec-pin-error-inj.c -- 2.16.1
