Re: [PATCH v3 0/2] scsi: libsas: Support spinup notification for SAS devices

[John Garry]

On 04/08/2026 10:30, yangxingui wrote:
> > How would other SAS HBAs which use libsas handle this scenario? Since 
> > they have FW, would the FW automatically issue this NOTIFY(ENABLE 
> > SPINUP)?
> >
> > I just wonder why hisi_sas seems to be only driver which would need this.
>
> Thanks for the question. This affects only SAS HDDs. I checked pm8001, 
> isci, and aic94xx — all handle NOTIFY(ENABLE SPINUP) at the driver level:
>
> - pm8001: sends once at phy-up, then mdelay(200) — comment: "delay a 
> moment to wait disk to spinup" — before notifying libsas.
>
> - isci: enables hardware periodic insertion during link idle (ENABLE bit 
> in notify_enable_spinup_control), cleared at phy stop.
>
> - aic94xx: enables microcode periodic insertion during link idle 
> (NOTIFY_TIMER_TIMEOUT = 500ms interval), stops at phy down.
>
> hisi_sas also calls sl_notify_ssp() at phy-up, but the NOTIFY_EN bit is 
> held for only 1ms — msleep(1) between setting and clearing — before 
> immediately notifying libsas.
>
> The root cause appears to be that 1ms is insufficient compared to 
> pm8001's 200ms. An alternative to hisi_sas would be to simply increase 
> the hold time in sl_notify_ssp() to match pm8001's approach, keeping the 
> fix within hisi_sas.
>
> Would you prefer this simpler approach, or do you still see value in the 
> libsas-level sense detection and callback from hisi_sas? ^-^

I think that if you can resolve this in the LL driver then that would be 
better.