poma <pomidorabelisima@xxxxxxxxx> writes:
> On 17.03.2016 19:02, Jes Sorensen wrote:
>> Jes Sorensen <Jes.Sorensen@xxxxxxxxxx> writes:
>>> Xose Vazquez Perez <xose.vazquez@xxxxxxxxx> writes:
>>>> Hi,
>>>>
>>>> If I do:
>>>> # echo "0bda 8176" > /sys/bus/usb/drivers/rtl8xxxu/new_id
>>>
>>> Hi Xose,
>>>
>>> Yes please don't do that. The rtl8xxxu driver relies on the .driver_info
>>> field in struct use_device_id to carry information for the different
>>> types of devices. If you hot add a device like above, the driver will
>>> fail because that field now contains a NULL pointer.
>>>
>>> I should probably add a check for it in the probe function, but it will
>>> simply be there to spit out a warning that it doesn't work to hot add a
>>> device like this.
>>>
>>> If you build it with CONFIG_RTL8XXXU_UNTESTED the 0bda:8176 should be
>>> included in the device list.
>>>
>>> Cheers,
>>> Jes
>>
>> Hi Xose,
>>
>> I added the following patch to my tree to avoid this.
>>
>> Cheers,
>> Jes
>>
>> commit 9202f4947aac1d60084ee79c9b5294eb42ba59dc
>> Author: Jes Sorensen <Jes.Sorensen@xxxxxxxxxx>
>> Date: Thu Mar 17 13:53:48 2016 -0400
>>
>> rtl8xxxu: Fix OOPS if user tries to add device via /sys
>>
>> This driver relies on driver_info in struct usb_device_id, hence
>> adding a device via /sys/bus/usb/drivers/rtl8xxxu/new_id would result
>> in a NULL pointer dereference.
>>
>> Instead print a message and return -ENODEV
>>
>> Reported-by: Xose Vazquez Perez <xose.vazquez@xxxxxxxxx>
>> Signed-off-by: Jes Sorensen <Jes.Sorensen@xxxxxxxxxx>
>>
>> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.c
>> index 8d893f4..55fc00e 100644
>> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.c
>> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.c
>> @@ -9671,6 +9671,15 @@ static int rtl8xxxu_probe(struct usb_interface *interface,
>>
>> udev = usb_get_dev(interface_to_usbdev(interface));
>>
>> + if (!id->driver_info) {
>> + dev_warn(&udev->dev,
>> + "rtl8xxxu relies on driver_info in struct usb_device_id.\n");
>> + dev_warn(&udev->dev,
>> + "Adding a device via /sys/bus/usb/drivers/rtl8xxxu/new_id is not supported!\n");
>> + ret = -ENODEV;
>> + goto exit;
>> + }
>> +
>> switch (id->idVendor) {
>> case USB_VENDOR_ID_REALTEK:
>> switch(id->idProduct) {
>
> Dynamic adding and removing a new device IDs to a USB device drivers
> via /sys/bus/usb/drivers/.../[new_id|remove_id]
> https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-bus-usb
>
> is not supported only with rtl8xxxu?
Dynamically adding one will not work. The driver relies on driver_info
in struct usb_device_id() to carry the struct fileops associated with
the device type and you cannot specify this via the USB add operation.
Jes
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