From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: michael@ellerman.id.au
Cc: linuxppc-dev@ozlabs.org
Subject: Re: [PATCH 3/4] Simplify rtas_change_msi() error semantics
Date: Tue, 02 Oct 2007 16:24:13 +1000 [thread overview]
Message-ID: <1191306253.6310.106.camel@pasglop> (raw)
In-Reply-To: <1191304690.6593.8.camel@concordia>
On Tue, 2007-10-02 at 15:58 +1000, Michael Ellerman wrote:
> > Looks allright, just a question tho... what do we do if it fails ?
> Do we
> > try to fallback to a lower number of MSIs ? Or what ? Dead device ?
>
> That's all up to the device driver. In theory the driver could try again
> with a lower count - but that might require extra logic in the driver to
> handle shared irq handlers etc. In practice I think the current drivers
> will just fail.
Question is badly phrased.. I meant something more like... what do we do
if RTAS returns a lower count ?
That is, we end up with that device with that lower count of MSIs
enabled, we fail at the driver level, do we still somewhat keep track ?
Drivers might assume that means it can use LSIs no ? which may not be
the case... Shouldn't we try to switch back to LSI mode (or does the
RTAS interface doesnt allow it ?)
Ben.
next prev parent reply other threads:[~2007-10-02 6:24 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-20 6:36 [PATCH 1/4] Simplify error logic in u3msi_setup_msi_irqs() Michael Ellerman
2007-09-20 6:36 ` [PATCH 2/4] Simplify error logic in rtas_setup_msi_irqs() Michael Ellerman
2007-10-02 5:21 ` Benjamin Herrenschmidt
2007-09-20 6:36 ` [PATCH 3/4] Simplify rtas_change_msi() error semantics Michael Ellerman
2007-10-02 5:23 ` Benjamin Herrenschmidt
2007-10-02 5:58 ` Michael Ellerman
2007-10-02 6:24 ` Benjamin Herrenschmidt [this message]
2007-10-02 7:40 ` Michael Ellerman
2007-10-02 8:37 ` Benjamin Herrenschmidt
2007-09-20 6:36 ` [PATCH 4/4] Inline u3msi_compose_msi_msg() Michael Ellerman
2007-10-02 5:24 ` Benjamin Herrenschmidt
2007-10-02 5:21 ` [PATCH 1/4] Simplify error logic in u3msi_setup_msi_irqs() Benjamin Herrenschmidt
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