On Mon, 20 Aug 2018 13:50:13 +0200
Theo Buehler <[email protected]> wrote:
> On Thu, Aug 16, 2018 at 09:51:32PM +0200, Frank Groeneveld wrote:
>> I haven't been able to type the passphrase of my softraid device on
>> boot when using an external keyboard on my Thinkpad X260. Finally I
>> had some time to debug this problem and this is what I discovered.
>> 
>> On a different laptop with EFI, the ReadKeyStroke call will not return
>> a packet when shift is pressed on the external keyboard. On the
>> Thinkpad however, a packet is returned with UnicodeChar == 0, which
>> results in a wrong passphrase being used.
>> 
>> This seems like a bug in the firmware to me, because according to some
>> EFI specifications I found online, this should not return a packet.
>> I've attached a simple patch that fixes this, but I'm not sure whether
>> this might break things on different systems.
> 
> I can't comment on the technical side of this patch but I can confirm
> that it allows me to enter the password from an external keyboard with
> my x280.

In the spec,

| The UnicodeChar is the actual printable character or is zero if the
| key does not represent a printable character (control key, function
| key, etc.).

It seems that UnicodeChar can be zero.  So I think the diff is OK even
on the spec.

If there is no futher comment I'll commit it.  Thanks.

--yasuoka

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