From: Marc Zyngier <maz@kernel.org>
To: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
Bjorn Helgaas <bhelgaas@google.com>
Cc: Frank Wunderlich <frank-w@public-files.de>,
Thierry Reding <treding@nvidia.com>,
Thomas Gleixner <tglx@linutronix.de>,
Rob Herring <robh@kernel.org>, Will Deacon <will@kernel.org>,
"K. Y. Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Michael Kelley <mikelley@microsoft.com>,
Wei Liu <wei.liu@kernel.org>,
Thierry Reding <thierry.reding@gmail.com>,
Jonathan Hunter <jonathanh@nvidia.com>,
Ryder Lee <ryder.lee@mediatek.com>,
Marek Vasut <marek.vasut+renesas@gmail.com>,
Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
Michal Simek <michal.simek@xilinx.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-hyperv@vger.kernel.org, linux-tegra@vger.kernel.org,
linux-mediatek@lists.infradead.org,
linux-renesas-soc@vger.kernel.org, kernel-team@android.com
Subject: [PATCH v2 14/15] PCI/MSI: Document the various ways of ending up with NO_MSI
Date: Mon, 22 Mar 2021 18:46:13 +0000 [thread overview]
Message-ID: <20210322184614.802565-15-maz@kernel.org> (raw)
In-Reply-To: <20210322184614.802565-1-maz@kernel.org>
We have now 4 ways of ending up with NO_MSI being set.
Document them.
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
drivers/pci/msi.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index d9c73c173c14..425abcdfcaca 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -871,8 +871,16 @@ static int pci_msi_supported(struct pci_dev *dev, int nvec)
* Any bridge which does NOT route MSI transactions from its
* secondary bus to its primary bus must set NO_MSI flag on
* the secondary pci_bus.
- * We expect only arch-specific PCI host bus controller driver
- * or quirks for specific PCI bridges to be setting NO_MSI.
+ *
+ * The NO_MSI flag can either be set directly by:
+ * - arch-specific PCI host bus controller drivers (deprecated)
+ * - quirks for specific PCI bridges
+ *
+ * or indirectly by platform-specific PCI host bridge drivers by:
+ * - unconditionally advertising the 'no_msi' property
+ * - advertising the 'msi_domain' property, which results in
+ * the NO_MSI flag when no MSI domain is found for this bridge
+ * at probe time.
*/
for (bus = dev->bus; bus; bus = bus->parent)
if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
--
2.29.2
next prev parent reply other threads:[~2021-03-22 18:54 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-22 18:45 [PATCH v2 00/15] PCI/MSI: Getting rid of msi_controller, and other cleanups Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 01/15] PCI: tegra: Convert to MSI domains Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 02/15] PCI: rcar: Don't allocate extra memory for the MSI capture address Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 03/15] PCI: rcar: Convert to MSI domains Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 04/15] PCI: xilinx: Don't allocate extra memory for the MSI capture address Marc Zyngier
2021-03-24 12:35 ` Bharat Kumar Gogada
2021-03-24 12:55 ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 05/15] PCI: xilinx: Convert to MSI domains Marc Zyngier
2021-03-24 12:42 ` Bharat Kumar Gogada
2021-03-24 13:15 ` Marc Zyngier
2021-03-24 13:56 ` Bharat Kumar Gogada
2021-03-24 14:45 ` Marc Zyngier
2021-03-25 4:13 ` Bharat Kumar Gogada
2021-03-22 18:46 ` [PATCH v2 06/15] PCI: hv: Drop msi_controller structure Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 07/15] PCI/MSI: Drop use of msi_controller from core code Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 08/15] PCI/MSI: Kill msi_controller structure Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 09/15] PCI/MSI: Kill default_teardown_msi_irqs() Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 10/15] PCI/MSI: Let PCI host bridges declare their lack of MSI handling Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 11/15] PCI: mediatek: Advertise " Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 12/15] PCI/MSI: Let PCI host bridges declare their reliance on MSI domains Marc Zyngier
2021-03-23 11:45 ` Robin Murphy
2021-03-23 18:09 ` Marc Zyngier
2021-03-23 19:04 ` Robin Murphy
2021-03-24 13:19 ` Lorenzo Pieralisi
2021-03-24 16:11 ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 13/15] PCI/MSI: Make pci_host_common_probe() declare its " Marc Zyngier
2021-03-22 18:46 ` Marc Zyngier [this message]
2021-03-22 18:46 ` [PATCH v2 15/15] PCI: Refactor HT advertising of NO_MSI flag Marc Zyngier
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