[PATCH 4/6] usb: kbd: Ignore Yubikeys

[Janne Grunau]

Hej,

On Wed, Feb 21, 2024, at 13:41, Marek Vasut wrote:
> On 2/21/24 08:25, Janne Grunau via B4 Relay wrote:
>> From: Hector Martin <marcan at marcan.st>
>> 
>> We currently only support one USB keyboard device, but some devices
>> emulate keyboards for other purposes. Most commonly, people run into
>> this with Yubikeys, so let's ignore those.
>> 
>> Even if we end up supporting multiple keyboards in the future, it's
>> safer to ignore known non-keyboard devices.
>> 
>> Signed-off-by: Hector Martin <marcan at marcan.st>
>> ---
>>   common/usb_kbd.c | 19 +++++++++++++++++++
>>   1 file changed, 19 insertions(+)
>> 
>> diff --git a/common/usb_kbd.c b/common/usb_kbd.c
>> index 4cbc9acb73..774d3555d9 100644
>> --- a/common/usb_kbd.c
>> +++ b/common/usb_kbd.c
>> @@ -120,6 +120,15 @@ struct usb_kbd_pdata {
>>   
>>   extern int __maybe_unused net_busy_flag;
>>   
>> +/*
>> + * Since we only support one usbkbd device in the iomux,
>> + * ignore common keyboard-emulating devices that aren't
>> + * real keyboards.
>> + */
>> +const uint16_t vid_blocklist[] = {
>> +	0x1050, /* Yubico */
>> +};
>> +
>>   /* The period of time between two calls of usb_kbd_testc(). */
>>   static unsigned long kbd_testc_tms;
>>   
>> @@ -465,6 +474,7 @@ static int usb_kbd_probe_dev(struct usb_device *dev, unsigned int ifnum)
>>   	struct usb_endpoint_descriptor *ep;
>>   	struct usb_kbd_pdata *data;
>>   	int epNum;
>> +	int i;
>>   
>>   	if (dev->descriptor.bNumConfigurations != 1)
>>   		return 0;
>> @@ -480,6 +490,15 @@ static int usb_kbd_probe_dev(struct usb_device *dev, unsigned int ifnum)
>>   	if (iface->desc.bInterfaceProtocol != USB_PROT_HID_KEYBOARD)
>>   		return 0;
>>   
>> +	for (i = 0; i < ARRAY_SIZE(vid_blocklist); i++) {
>> +		if (dev->descriptor.idVendor == vid_blocklist[i]) {
>> +			printf("Ignoring keyboard device 0x%x:0x%x\n",
>> +			       dev->descriptor.idVendor,
>> +			       dev->descriptor.idProduct);
>> +			return 0;
>> +		}
>> +	}
>
> I vaguely recall a discussion about previous version of this, I think 
> the suggestion was to make the list of ignored devices configurable via 
> environment variable, so users can add to that list from U-Boot shell. 
> Would it be possible to make it work this way ?

oh, I completely forgot that this patch was already submitted. I briefly looked through asahi tree for related patches and did not check whether this was previously submitted.
I've added environment based blocking as separate patch with blocking either complete vendor IDs or vendor, product ID combinations. A separate patch to simplify authorship tracking and the implementation doesn't share any code.

Janne