From f9d76d15072caf1ec5558fa7cc6d93c7b9d33488 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Tue, 10 May 2022 11:51:29 -0400 Subject: [PATCH] USB: gadget: Add ID numbers to gadget names Putting USB gadgets on a new bus of their own encounters a problem when multiple gadgets are present: They all have the same name! The driver core fails with a "sys: cannot create duplicate filename" error when creating any of the /sys/bus/gadget/devices/ symbolic links after the first. This patch fixes the problem by adding a ".N" suffix to each gadget's name when the gadget is registered (where N is a unique ID number), thus making the names distinct. Reported-and-tested-by: Geert Uytterhoeven Signed-off-by: Alan Stern Reviewed-by: Geert Uytterhoeven Fixes: fc274c1e9973 ("USB: gadget: Add a new bus for gadgets") Link: https://lore.kernel.org/r/YnqKAXKyp9Vq/pbn@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/udc/core.c | 16 ++++++++++++++-- include/linux/usb/gadget.h | 2 ++ 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index 3281d8a..7886497 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -23,6 +24,8 @@ #include "trace.h" +static DEFINE_IDA(gadget_id_numbers); + static struct bus_type gadget_bus_type; /** @@ -1248,7 +1251,6 @@ static void usb_udc_nop_release(struct device *dev) void usb_initialize_gadget(struct device *parent, struct usb_gadget *gadget, void (*release)(struct device *dev)) { - dev_set_name(&gadget->dev, "gadget"); INIT_WORK(&gadget->work, usb_gadget_state_work); gadget->dev.parent = parent; @@ -1304,12 +1306,21 @@ int usb_add_gadget(struct usb_gadget *gadget) usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED); udc->vbus = true; + ret = ida_alloc(&gadget_id_numbers, GFP_KERNEL); + if (ret < 0) + goto err_del_udc; + gadget->id_number = ret; + dev_set_name(&gadget->dev, "gadget.%d", ret); + ret = device_add(&gadget->dev); if (ret) - goto err_del_udc; + goto err_free_id; return 0; + err_free_id: + ida_free(&gadget_id_numbers, gadget->id_number); + err_del_udc: flush_work(&gadget->work); device_del(&udc->dev); @@ -1417,6 +1428,7 @@ void usb_del_gadget(struct usb_gadget *gadget) kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE); flush_work(&gadget->work); device_del(&gadget->dev); + ida_free(&gadget_id_numbers, gadget->id_number); device_unregister(&udc->dev); } EXPORT_SYMBOL_GPL(usb_del_gadget); diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h index cf7af8a..3ad58b7 100644 --- a/include/linux/usb/gadget.h +++ b/include/linux/usb/gadget.h @@ -386,6 +386,7 @@ struct usb_gadget_ops { * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag * indicates that it supports LPM as per the LPM ECN & errata. * @irq: the interrupt number for device controller. + * @id_number: a unique ID number for ensuring that gadget names are distinct * * Gadgets have a mostly-portable "gadget driver" implementing device * functions, handling all usb configurations and interfaces. Gadget @@ -446,6 +447,7 @@ struct usb_gadget { unsigned connected:1; unsigned lpm_capable:1; int irq; + int id_number; }; #define work_to_gadget(w) (container_of((w), struct usb_gadget, work)) -- 2.7.4