From: Manu Abraham <abraham.manu@gmail.com>
To: Roland Dreier <rdreier@cisco.com>
Cc: Greg KH <greg@kroah.com>,
linux-pci@atrey.karlin.mff.cuni.cz,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: PCIE
Date: Sat, 26 May 2007 19:03:12 +0400 [thread overview]
Message-ID: <46584C30.4030206@gmail.com> (raw)
In-Reply-To: <ada1wh560u1.fsf@cisco.com>
Roland Dreier wrote:
> > I am now wondering whether the usage of MSI would help in this case and
> > that i should be using enable_msi before request_irq ?
>
> MSI interrupts are never shared. So if pci_enable_msi() succeeds, you
> can be sure that the interrupts you get with that IRQ number are
> coming from your device.
>
i presume then i shouldn't be using IRQF_SHARED, if using MSI.
Another question would be if the device supports multiple messages, MSIX
should be used ?
In such a context, if i request for say more than the messages that i
need, say i request 16 messages, but use only 1 or 2, that does bear any
consequences ?
> But using MSI does not work on all systems, so your driver needs to
> work with standard (possibly shared) INTx interrupts too. And you
> should probably provide at least a module flag to disable the use of
> MSI, to avoid problems on buggy systems.
I should probably look for CONFIG_PCI_MSI and check whether the system
supports MSI pci_enable_msi() ?
next prev parent reply other threads:[~2007-05-26 15:05 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-23 12:15 PCIE Manu Abraham
2007-05-23 15:59 ` PCIE Greg KH
2007-05-23 20:59 ` PCIE Manu Abraham
2007-05-23 21:10 ` PCIE Roland Dreier
2007-05-23 22:11 ` PCIE Manu Abraham
2007-05-23 22:23 ` PCIE Roland Dreier
2007-05-23 23:03 ` PCIE Manu Abraham
2007-05-23 23:51 ` PCIE Roland Dreier
2007-05-24 0:07 ` PCIE Manu Abraham
2007-05-24 22:32 ` PCIE Manu Abraham
2007-05-25 3:25 ` PCIE Roland Dreier
2007-05-26 15:03 ` Manu Abraham [this message]
2007-05-26 18:28 ` PCIE Grant Grundler
2007-05-26 19:27 ` PCIE Manu Abraham
2007-05-28 1:15 ` PCIE Roland Dreier
2007-05-28 1:25 ` PCIE Manu Abraham
2007-05-28 2:04 ` PCIE Manu Abraham
2007-05-28 2:24 ` PCIE Roland Dreier
2007-05-28 2:47 ` PCIE Manu Abraham
2007-05-26 22:49 ` PCIE David Miller
2007-05-26 22:57 ` PCIE Manu Abraham
2007-05-26 23:55 ` PCIE Grant Grundler
2007-05-27 0:00 ` PCIE David Miller
2007-05-27 0:16 ` PCIE Grant Grundler
2007-05-27 0:30 ` PCIE David Miller
2007-05-27 1:01 ` PCIE Manu Abraham
2007-05-27 1:49 ` PCIE Grant Grundler
2007-05-27 20:28 ` PCIE Manu Abraham
2007-05-28 1:10 ` PCIE Roland Dreier
2007-05-27 2:34 ` PCIE H. Peter Anvin
2007-05-27 7:40 ` PCIE David Miller
2007-05-27 20:31 ` PCIE Manu Abraham
2007-05-28 1:05 ` PCIE Roland Dreier
2007-05-28 1:03 ` PCIE Roland Dreier
2007-05-28 2:54 ` PCIE David Miller
2007-05-28 4:18 ` PCIE Grant Grundler
2007-05-28 5:23 ` PCIE H. Peter Anvin
2007-05-28 5:22 ` PCIE H. Peter Anvin
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