From: Arnd Bergmann <arnd@arndb.de>
To: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
Grant Likely <grant.likely@secretlab.ca>,
Russell King <linux@arm.linux.org.uk>,
linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
devicetree-discuss@lists.ozlabs.org,
Lior Amsalem <alior@marvell.com>, Andrew Lunn <andrew@lunn.ch>,
Jason Cooper <jason@lakedaemon.net>,
Maen Suleiman <maen@marvell.com>,
Thierry Reding <thierry.reding@avionic-design.de>,
Gregory Clement <gregory.clement@free-electrons.com>,
Ezequiel Garcia <ezequiel.garcia@free-electrons.com>,
Olof Johansson <olof@lixom.net>,
Tawfik Bayouk <tawfik@marvell.com>,
Jason Gunthorpe <jgunthorpe@obsidianresearch.com>,
Mitch Bradley <wmb@firmworks.com>,
Andrew Murray <andrew.murray@arm.com>
Subject: Re: [RFCv1 07/11] irqchip: armada-370-xp: add MSI support to interrupt controller driver
Date: Tue, 26 Mar 2013 21:15:40 +0000 [thread overview]
Message-ID: <201303262115.41200.arnd@arndb.de> (raw)
In-Reply-To: <1364316746-8702-8-git-send-email-thomas.petazzoni@free-electrons.com>
On Tuesday 26 March 2013, Thomas Petazzoni wrote:
> + msimask = readl_relaxed(per_cpu_int_base +
> + ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS)
> + & PCI_MSI_DOORBELL_MASK;
> +
> + writel(~PCI_MSI_DOORBELL_MASK, per_cpu_int_base +
> + ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS);
> +
Upon reading this code again, I stumbled over the barriers. You use
a readl_relaxed() without barrier but a writel() with barrier. Is
that intentional? Are you sure that you don't need a full readl()
to guarantee that all inbound DMA that was sent by the device before
the MSI message has arrived by the time the interrupt handler function
is called? It depends on the implementation of the MSI controller whether
that guarantee is already made by the fact that you are handling the
interrupt.
Arnd
next prev parent reply other threads:[~2013-03-26 21:16 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-26 16:52 [RFCv1 00/11] MSI support for Marvell EBU PCIe driver Thomas Petazzoni
2013-03-26 16:52 ` [RFCv1 01/11] arm: mvebu: move L2 cache initialization in init_early() Thomas Petazzoni
2013-03-26 16:53 ` Arnd Bergmann
2013-03-26 17:02 ` Thomas Petazzoni
2013-03-27 1:53 ` Rob Herring
2013-03-26 16:52 ` [RFCv1 02/11] irqchip: move IRQ driver for Armada 370/XP Thomas Petazzoni
2013-03-26 16:54 ` Arnd Bergmann
2013-03-26 16:52 ` [RFCv1 03/11] irqchip: armada-370-xp: move IRQ handler to avoid forward declaration Thomas Petazzoni
2013-03-26 16:52 ` [RFCv1 04/11] irqchip: armada-370-xp: slightly cleanup irq controller driver Thomas Petazzoni
2013-03-26 16:52 ` [RFCv1 05/11] arm: mvebu: do not duplicate the mpic alias Thomas Petazzoni
2013-03-26 16:52 ` [RFCv1 06/11] irqchip: armada-370-xp: use a separate mpic node Thomas Petazzoni
2013-03-26 16:52 ` [RFCv1 07/11] irqchip: armada-370-xp: add MSI support to interrupt controller driver Thomas Petazzoni
2013-03-26 17:07 ` Arnd Bergmann
2013-03-26 17:17 ` Thomas Petazzoni
2013-03-26 18:38 ` Arnd Bergmann
2013-03-26 20:46 ` Thomas Petazzoni
2013-03-26 21:10 ` Arnd Bergmann
2013-03-26 21:37 ` Thomas Petazzoni
2013-03-26 21:53 ` Arnd Bergmann
2013-03-26 21:14 ` Jason Gunthorpe
2013-03-26 21:41 ` Thomas Petazzoni
2013-03-26 18:02 ` Jason Gunthorpe
2013-03-26 21:16 ` Thomas Petazzoni
2013-03-26 21:31 ` Arnd Bergmann
2013-03-26 21:47 ` Thomas Petazzoni
2013-03-26 21:55 ` Jason Gunthorpe
2013-03-26 22:04 ` Arnd Bergmann
2013-03-26 22:06 ` Thomas Petazzoni
2013-03-26 22:26 ` Jason Gunthorpe
2013-03-26 21:15 ` Arnd Bergmann [this message]
2013-03-26 21:42 ` Thomas Petazzoni
2013-03-26 16:52 ` [RFCv1 08/11] PCI: Introduce new MSI chip infrastructure Thomas Petazzoni
2013-04-08 22:28 ` Bjorn Helgaas
2013-04-09 8:11 ` Andrew Murray
2013-04-09 8:22 ` Thierry Reding
2013-04-09 8:25 ` Andrew Murray
2013-04-09 8:18 ` Thierry Reding
2013-03-26 16:52 ` [RFCv1 09/11] pci: mvebu: add MSI support Thomas Petazzoni
2013-03-27 10:07 ` Andrew Murray
2013-04-08 22:29 ` Bjorn Helgaas
2013-05-30 12:15 ` Thierry Reding
2013-05-30 18:13 ` Bjorn Helgaas
2013-03-26 16:52 ` [RFCv1 10/11] arm: mvebu: enable MSI support in DT Thomas Petazzoni
2013-03-26 16:52 ` [RFCv1 11/11] arm: mvebu: enable PCI MSI support in defconfig Thomas Petazzoni
2013-03-26 17:05 ` [RFCv1 00/11] MSI support for Marvell EBU PCIe driver Thomas Petazzoni
2013-03-26 17:18 ` Arnd Bergmann
2013-03-26 17:21 ` Thomas Petazzoni
2013-04-04 9:16 ` Ezequiel Garcia
2013-04-04 9:29 ` Thomas Petazzoni
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