Messages in this thread | | | From | Alexander Shishkin <> | Subject | Re: [PATCH v3 01/11] stm class: Introduce an abstraction for System Trace Module devices | Date | Thu, 30 Jul 2015 09:37:53 +0300 |
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Chunyan Zhang <zhang.lyra@gmail.com> writes:
> Sure, I mean, the root reason of this problem is here ( i.e. > "stm_core_up" was zero then): > if (!stm_core_up) > return -EPROBE_DEFER; > > Why it was zero? > Because the function (i.e. stm_core_init() ) in which "stm_core_up" > would be added one hasn't been executed at this moment. It would be > executed on module_init stage for you this version of patch.
Again, this is the indented behavior.
> The reason of this warning is: > After stm_probe() failed, clk_core_disable() would be called from > amba_put_disable_pclk(), then WARN_ON() happened: > if (WARN_ON(core->enable_count == 0)) > return; > > I'm guessing the reason why "core->enable_count" was 0 at this moment is: > I don't know who created a thread to process the > amba_pm_runtime_suspend(), in which clk_core_disable() was already > called, "core->enable_count" was, of course, cleared to zero then. > And this thread run before amba_put_disable_pclk(pcdev) which is just > the one called from amba_probe() after > "->probe"(i.e. stm_probe in this case) returning a non-zero value.
No, this is guesswork. In amba_probe(), clocks are enabled for the drv->probe() and then disabled afterwards and that's where the refcount ends up unbalanced, the probe is the culprit.
I can debug your driver for you but you'll at least need to put the code up somewhere so I can see it.
Regards, -- Alex
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