[igt-dev] [PATCH i-g-t] i915_module_load: Unload the module before exiting the subtest

[Modem, Bhanuprakash]

On Tue-15-03-2022 05:13 pm, Petri Latvala wrote:
> On Tue, Mar 15, 2022 at 12:25:09PM +0530, Bhanuprakash Modem wrote:
>> On DP-MST setup, after execution of "reload" subtest, i915
>> became unloadable. And this is effecting the next subtest
>> "reload-no-display".
>>
>> Observing below error, if we run all subtests of i915_module_load
>> (or) run "reload" & "reload-no-display" in same order using the
>> igt_runner. But not seen any issue if we run each subtest individually.
>>
>> $ ./igt_runner -o -l verbose -s --test-list tests.txt --use-watchdog ../tests/ results/
>> (or)
>> $ ./build/tests/i915_module_load
>>    Starting subtest: reload
>>    ...
>>    Subtest reload: SUCCESS (3.780s)
>>
>>    Starting subtest: reload-no-display
>>    (i915_module_load:42617) igt_kmod-WARNING: Could not unload i915
>>    Module                   Used by
>>    i915                     1
>>    ...
>>    Reloading i915 with disable_display=1
>>    Module i915 already inserted
>>    Could not load i915
>>    Subtest reload-no-display: FAIL (1.998s)
>>
>> $ ./build/tests/i915_module_load --r reload
>>    Starting subtest: reload
>>    ...
>>    Subtest reload: SUCCESS (5.562s)
>> $ ./build/tests/i915_module_load --r reload-no-display
>>    Starting subtest: reload-no-display
>>    ...
>>    Subtest reload-no-display: SUCCESS (7.995s)
>>
>> This patch will unload the module before exiting the subtest. So
>> that we can make sure that the module is unloaded.
> 
> Does it succeed in there? Or does this just make sure that the failure
> is caught in the right place? What is actually holding the reference
> to i915.ko?

Not sure who is holding the ref to i915. lsmod showing it is used by 1 
but not showing who actually holding it.

Module                   Used by
i915                     1

But with this fix, there is no such failures mentioned in commit msg.

- Bhanu

> 
>