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: 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); } > >>> + > >> > >> ... > >
