[PATCH v1] ufs: core: decouple CQE processing from spinlock critical section

[Bart Van Assche]

On 5/14/26 1:26 AM, peter.wang at mediatek.com wrote:
> 4. In both ufshcd_mcq_compl_all_cqes_lock() and
>     ufshcd_mcq_poll_cqe_lock(), snapshot the starting CQE pointer before
>     advancing the head slot under the spinlock, then process the collected
>     CQEs after releasing the lock using the new helper.

This can't work reliably. ufshcd_mcq_poll_cqe_lock() may be called
concurrently from different CPU cores, e.g. from a UFS completion
interrupt and from ufshcd_poll(). Processing CQEs without holding
hwq->cq_lock may lead to overwriting of CQEs before these have been
processed.

Thanks,

Bart.