Messages in this thread | | | From | Ulf Hansson <> | Date | Fri, 18 May 2018 11:07:02 +0200 | Subject | Re: [PATCH] PM / runtime: Fixup reference counting of device link suppliers at probe |
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On 18 May 2018 at 10:58, Rafael J. Wysocki <rafael@kernel.org> wrote: > On Fri, May 18, 2018 at 10:48 AM, Ulf Hansson <ulf.hansson@linaro.org> wrote: >> In the driver core, before it invokes really_probe() it runtime resumes the >> suppliers for the device via calling pm_runtime_get_suppliers(), which also >> increases the runtime PM usage count for each of the available supplier. >> >> This makes sense, as to be able to allow the consumer device to be probed >> by its driver. However, if the driver decides to add a new supplier link >> during ->probe(), hence updating the list of suppliers, > > Do any of the existing drivers do that?
Yes.
At least these, but possibly even more...
drivers/gpu/drm/rockchip/rockchip_drm_drv.c drivers/gpu/drm/tegra/dc.c drivers/gpu/ipu-v3/ipu-prg.c drivers/pci/dwc/pci-dra7xx.c
> >> the following call to pm_runtime_put_suppliers(), invoked after really_probe() >> in the driver core, we get into trouble.
Kind regards Uffe
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