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SubjectRe: [PATCH] eHCA: Add "Modify Port" verb
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Roland Dreier <rdreier@cisco.com> wrote on 23.04.2007 21:20:14:

> > + if (hipz_h_query_port(shca->ipz_hca_handle, port, rblock) !=
H_SUCCESS) {
> > + ehca_err(&shca->ib_device, "Can't query port properties");
> > + ret = -EINVAL;
> > + goto modify_port1;
> > + }
> > +
> > + cap = (rblock->capability_mask | props->set_port_cap_mask)
> > + & ~props->clr_port_cap_mask;
> > +
> > + hret = hipz_h_modify_port(shca->ipz_hca_handle, port,
> > + cap, props->init_type, port_modify_mask);

> Is this thread-safe? What if two different bits are set at the same
> time from two different threads? It seems that both calls could get
> the same result from hipz_h_query_port(), and then the second call to
> hipz_h_modify_port() would overwrite the first call.

Yes, you're so right.

> You could look at the implementation in mthca to see the locking I
> used there.

I'll do that, thanks for the hint!

Joachim

---
Joachim Fenkes -- eHCA Linux Driver Developer and Hardware Tamer
IBM Deutschland Entwicklung GmbH -- Dept. 3627 (I/O Firmware Dev. 2)
Schoenaicher Strasse 220 -- 71032 Boeblingen -- Germany
eMail: fenkes@de.ibm.com -- Phone: +49 7031 16 1239
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