The bravery continues with the next update of the in-kernel logic analyzer based on GPIO polling with local irqs disabled. It has been tested locally and remotely. It provided satisfactory results. Besides the driver, there is also a script which isolates a CPU to achieve the best possible result. I am aware of the latency limitations. However, the intention is for debugging only, not mass production. Especially for remote debugging and to get a first impression, this has already been useful. Documentation is within the patch, to get a better idea what this is all about. A branch is here: git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git renesas/gpio-logic-analyzer-v5 And an eLinux-wiki page with a picture of a result is here: https://elinux.org/Kernel_GPIO_Logic_analyzer Changes since last version: * increased version number to 5 to match internal and external numbering * added "SLOPPY" to the Kconfig symbol as well * addressed Geert's comments (typos and more 'unsigned int' usage). Thanks! * addressed Andy's comments (updated comment, use dev_err_probe, use '... || fail' pattern in script consequently). Thanks! I've used the analyzer in a few more scenarios and on another SoC (Renesas R-Car M3-W) and was happy with the outcome. Looking forward to other tests and comments. From my side this is good to go. Happy hacking, Wolfram Wolfram Sang (1): gpio: add sloppy logic analyzer using polling .../dev-tools/gpio-sloppy-logic-analyzer.rst | 71 ++++ Documentation/dev-tools/index.rst | 1 + drivers/gpio/Kconfig | 17 + drivers/gpio/Makefile | 1 + drivers/gpio/gpio-sloppy-logic-analyzer.c | 340 ++++++++++++++++++ tools/gpio/gpio-sloppy-logic-analyzer | 222 ++++++++++++ 6 files changed, 652 insertions(+) create mode 100644 Documentation/dev-tools/gpio-sloppy-logic-analyzer.rst create mode 100644 drivers/gpio/gpio-sloppy-logic-analyzer.c create mode 100755 tools/gpio/gpio-sloppy-logic-analyzer -- 2.30.2
