On Thu, Jul 30, 2015 at 2:37 PM, Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> wrote: > Chunyan Zhang <zhang.lyra@xxxxxxxxx> 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. The code has already been submitted like I said in the earlier emails, you may refer [1]. Thanks, Chunyan [1] https://lkml.org/lkml/2015/2/4/729 > > Regards, > -- > Alex > -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
