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| author | Alan Stern <stern@rowland.harvard.edu> | 2022-05-10 11:51:29 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-05-11 18:59:25 +0200 |
| commit | f9d76d15072caf1ec5558fa7cc6d93c7b9d33488 (patch) | |
| tree | ed7dfff99994add27e32f3b32c4b49bac3271d89 | |
| parent | a2673d570bd648851e00ac531bdf695f4ebb4f78 (diff) | |
| download | linux-f9d76d15072caf1ec5558fa7cc6d93c7b9d33488.tar.bz2 | |
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/<gadget-name>
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 <geert+renesas@glider.be>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
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 <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/gadget/udc/core.c | 16 | ||||
| -rw-r--r-- | 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 3281d8a3dae7..7886497253cc 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -12,6 +12,7 @@ #include <linux/module.h> #include <linux/device.h> #include <linux/list.h> +#include <linux/idr.h> #include <linux/err.h> #include <linux/dma-mapping.h> #include <linux/sched/task_stack.h> @@ -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 cf7af8a0a6e9..3ad58b7a0824 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)) |