Re: [PATCH] scsi: ufs: core: Avoid sleeping in hard interrupt context when PREEMP_RT is enabled.

[Bart Van Assche]

On 6/30/26 7:15 AM, Sebastian Andrzej Siewior wrote:
>  From ufshcd_intr():
> |         intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
> |         enabled_intr_status = intr_status & ufshcd_readl(hba, REG_INTERRUPT_ENABLE);
> |
> |         ufshcd_writel(hba, intr_status, REG_INTERRUPT_STATUS);
>
> What does this do? Does it disable the IRQ source? If so then
> IRQF_ONESHOT should be removed.

Writing into the REG_INTERRUPT_STATUS register clears the bits that are
set in the first argument of writel().

> |         /* Directly handle interrupts since MCQ ESI handlers does the hard job */
> |         return ufshcd_sl_intr(hba, enabled_intr_status);
>
> If not, why is this not part of the threaded handler?
If MCQ is disabled, ufshcd_sl_intr() processes all types of interrupts.
If MCQ is enabled, the ESI interrupt handlers process I/O completions
and ufshcd_sl_intr() processes the remaining interrupt types.

Bart.