Messages in this thread | | | Date | Sat, 4 Nov 2023 09:35:11 +0100 | Subject | Re: RE: RE: [PATCH v6 1/2] usb: dwc3: add Realtek DHC RTD SoC dwc3 glue layer driver | From | Christophe JAILLET <> |
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Le 03/11/2023 à 11:54, Stanley Chang[昌育德] a écrit : > Hi Christophe, > >> Le 01/11/2023 à 07:27, Stanley Chang[昌育德] a écrit : >>> Hi CJ, >>> >>> I think these functions are not needed in remove function. >>> >>> In dwc3_rtk_probe_dwc3_core, >>> I have used >>> dwc3_node = of_get_compatible_child(node, "snps,dwc3"); and dwc3_pdev >>> = of_find_device_by_node(dwc3_node); >>> >>> So, I call these put functions. >>> platform_device_put(dwc3_pdev); >>> of_node_put(dwc3_node); >> >> Yes, but you call it only in the error handling path of the function. >> >> I wonder if they should also be called in the remove function in order to >> decrement the ref-counted reference. >> >> >> Same in __get_dwc3_maximum_speed(), the reference taken by: >> dwc3_np = of_get_compatible_child(np, "snps,dwc3"); is never released. >> >> >> See the comment at [1] to see what I mean. >> >> >> [1]: https://elixir.bootlin.com/linux/v6.6/source/drivers/of/base.c#L681 > > You are right! > For dwc3_pdev, dwc3_np or dwc3_node, I should add of_node_put to release them when the function exits. > https://elixir.bootlin.com/linux/v6.5.10/source/drivers/usb/dwc3/dwc3-meson-g12a.c#L567 > > I will add a patch to fix this. > > For example, > diff --git a/drivers/usb/dwc3/dwc3-rtk.c b/drivers/usb/dwc3/dwc3-rtk.c > index 590028e8fdcb..9d6f2a8bd6ce 100644 > --- a/drivers/usb/dwc3/dwc3-rtk.c > +++ b/drivers/usb/dwc3/dwc3-rtk.c > @@ -187,6 +187,7 @@ static enum usb_device_speed __get_dwc3_maximum_speed(struct device_node *np) > > ret = match_string(speed_names, ARRAY_SIZE(speed_names), maximum_speed); > > + of_node_put(dwc3_np); > return (ret < 0) ? USB_SPEED_UNKNOWN : ret; > } > > @@ -339,6 +340,8 @@ static int dwc3_rtk_probe_dwc3_core(struct dwc3_rtk *rtk) > > switch_usb2_role(rtk, rtk->cur_role); > > + platform_device_put(dwc3_pdev); > + of_node_put(dwc3_node); > return 0; > > err_pdev_put: >
LGTM.
CJ
> > Thanks, > Stanley > >> CJ >>> >>> Thanks, >>> Stanley >>> >>>> Hi, >>>> >>>> Is something like >>>> platform_device_put(dwc3_pdev); >>>> of_node_put(dwc3_node); >>>> needed in the remove function? >>>> >>>> (as done in the error handling path of dwc3_rtk_probe_dwc3_core()) >>>> >>>> Or should it be added at the end of dwc3_rtk_probe_dwc3_core() if the >>>> reference are nor needed anymore when we leave the function? >>>> >>>> CJ >>>> >>>>> + of_platform_depopulate(rtk->dev); } >>>>> + >>>> >>>> ... >>> >
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