Re: [PATCH v1 1/1] ufs: core: Add host quirk QUIRK_MCQ_EXPAND_QUEUE_SLOT

[Bart Van Assche]

On 10/25/23 01:56, Chun-Hung Wu wrote:
> This quirk needs to be enabled if the host controller cannot 
> distinguish queue full or empty.

From the UFSHCI 4.0 specification: "When the head and tail doorbells are
equal, the queue is empty. [ ... ] When the head and tail doorbells are
not equal, the queue contains queue entries."

How is it possible that a host controller cannot distinguish queue full
or queue empty? Which (head - tail) values cause trouble? More
information is needed.

Thanks,

Bart.