Re: [PATCH 1/5] scsi: hisi_sas: Add host_tagset_enable module param for v3 hw

[yangxingui]

On 2025/3/31 16:40, Niklas Cassel wrote:
> Hello Xingui,
>
> On Sat, Mar 29, 2025 at 05:49:47PM +0800, yangxingui wrote:
> > Hi，John
> >
> > On 2025/3/29 16:50, John Garry wrote:
> > > On 29/03/2025 07:32, Yihang Li wrote:
> > >
> > > +
> > >
> > > > From: Xingui Yang<yangxingui@xxxxxxxxxx>
> > > >
> > > > After driver exposes all HW queues and application submits IO to multiple
> > > > queues in parallel, if NCQ and non-NCQ commands are mixed to sata disk,
> > > > ata_qc_defer() causes non-NCQ commands to be requeued and possibly
> > > > repeated
> > > > forever.
> > >
> > > I don't think that it is a good idea to mask out bugs with module
> > > parameters.
> > >
> > > Was this the same libata/libsas issue reported some time ago?
> >
> > Yeah，related to this issue: https://lore.kernel.org/linux-block/eef1e927-c9b2-c61d-7f48-92e65d8b0418@xxxxxxxxxx/
> >
> > And, Niklas tried to help fix this problem:
> > https://lore.kernel.org/linux-scsi/ZynmfyDA9R-lrW71@ryzen/
> >
> > Considering that there is no formal solution yet. And our users rarely use
> > SATA disks and SAS disks together on a single machine. For this reason, they
> > can flexibly turn off the exposure of multiple queues in the scenario of
> > using only SATA disks. In addition, it is also convenient to conduct
> > performance comparison tests to expose multiple hardware queues and single
> > queues.
>
> The solution I sent is not good since it relies on EH.
>
> One would need to come up with a better solution to fix libsas drivers,
> possibly a workqueue.
>
> I think Damien is planning to add a workqueue submit path to libata,
> if so, perhaps we could base a better solution on top of that.

Thank you for your solution. As you said, we may need a better solution.

Thanks,
Xingui
.