Messages in this thread | | | Date | Mon, 8 Jun 2020 06:11:34 +0300 | From | Laurent Pinchart <> | Subject | Re: Re: [PATCH] media: vsp1: Fix runtime PM imbalance in vsp1_probe |
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Hi Dianghao,
On Mon, Jun 08, 2020 at 11:03:26AM +0800, dinghao.liu@zju.edu.cn wrote: > Hi Laurent, > > > > I wonder how many bugs we have today, and how many bugs will keep > > > appearing in the future, due to this historical design mistake :-( > > Good question. It's hard to say if this is a design mistake (some use > of this API does not check its return value and expects it always to > increment the usage counter). But it does make developers misuse it easier. > > > > This change looks good to me, but we also need a similar change in the > > > vsp1_device_get() function if I'm not mistaken. Could you combine both > > > in the same patch ? > > Thank you for your advice! I think you are right and I will fix this in the > next version of patch. > > > And actually, after fixing vsp1_device_get(), we should replace the > > pm_runtime_get_sync() call here with vsp1_device_get(), and the > > pm_runtime_put_sync() below with vsp1_device_put(), so there would be no > > need to call pm_runtime_put_sync() manually in the error path here. > > The parameter type of vsp1_device_get() and vsp1_device_put() is "struct > vsp1_device". If we want to use these two wrappers, we need to adjust their > parameter type to "struct platform_device" or "struct device", which may > lead to errors in other callers. Maybe we should leave it as it is.
The vsp1_probe() function has a struct vsp1_device whose dev field is populated by the time it needs to call pm_runtime_get_sync() and pm_runtime_get_put(), so I think you can use vsp1_device_get() and vsp1_device_put() as drop-in replacements without changing the parameters to these two functions.
-- Regards,
Laurent Pinchart
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