Messages in this thread | | | Date | Sun, 13 Jul 2014 08:46:41 -0700 | From | Guenter Roeck <> | Subject | Re: [PATCH v2] i2c: stub: Add support for SMBus block commands |
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On 07/13/2014 08:13 AM, Jean Delvare wrote: > On Sun, 13 Jul 2014 08:04:54 -0700, Guenter Roeck wrote: >> On 07/13/2014 12:21 AM, Jean Delvare wrote: >>> Hi Guenter, >>> >>> On Sat, 12 Jul 2014 08:05:49 -0700, Guenter Roeck wrote: >>>> Any idea how we could inject errors ? Error path testing would be quite useful. >>> >>> Good idea. This should probably be done with a sysfs attribute so that >>> it can be turned on and off as desired. Off by default, of course. Some >>> other subsystems already support error injection, you could check how >>> they are doing it, do that we do not diverge needlessly. >>> >>> Do you think there is any value in failing with different error codes, >>> or just -EIO is enough? >> >> How about writing the error code to return into the attribute ? >> Write anything negative, and it is returned as error. Write 0, >> and the driver works as normal. > > This is smart, I like it :) > >>> Do you think it should fail all the time when error injection is >>> enabled, or is there a value in having only a certain % of commands >>> fail? >> >> For my purposes I would want it to fail reliably. We could add some fanciness, >> though: Provide a second attribute which specifies how many operations should >> pass before the first failure. > > Let's start simple and just implement what you need. >
I would actually benefit from both. The ability to return an error unconditionally lets me test the first error path. The ability to return an error starting with the n-th transfer lets me test the n-th error path.
Guenter
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