From: Lucas Stach <l.stach@pengutronix.de>
To: Jingoo Han <jingoohan1@gmail.com>,
Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
linux-pci@vger.kernel.org, Tim Harvey <tharvey@gateworks.com>,
kernel@pengutronix.de, patchwork-lst@pengutronix.de
Subject: [PATCH] PCI: dwc: skip MSI init if MSIs have been explicitly disabled
Date: Wed, 27 Feb 2019 17:52:19 +0100 [thread overview]
Message-ID: <20190227165219.31911-1-l.stach@pengutronix.de> (raw)
Since 7c5925afbc58 (PCI: dwc: Move MSI IRQs allocation to IRQ domains
hierarchical API) the MSI init claims one of the controller IRQs as a
chained IRQ line for the MSI controller. On some designs, like the i.MX6,
this line is shared with a PCIe legacy IRQ. When the line is claimed for
the MSI domain, any device trying to use this legacy IRQs will fail to
request this IRQ line.
As MSI and legacy IRQs are already mutually exclusive on the DWC core,
as the core won't forward any legacy IRQs once any MSI has been enabled,
users wishing to use legacy IRQs already need to explictly disable MSI
support (usually via the pci=nomsi kernel commandline option). To avoid
any issues with MSI conflicting with legacy IRQs, just skip all of the
DWC MSI initalization, including the IRQ line claim, when MSI is disabled.
Fixes: c5925afbc58
(PCI: dwc: Move MSI IRQs allocation to IRQ domains hierarchical API)
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Tim Harvey <tharvey@gateworks.com>
---
drivers/pci/controller/dwc/pcie-designware-host.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index 29a05759a294..f4a8494f616b 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -433,7 +433,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
if (ret)
pci->num_viewport = 2;
- if (IS_ENABLED(CONFIG_PCI_MSI)) {
+ if (IS_ENABLED(CONFIG_PCI_MSI) && pci_msi_enabled()) {
/*
* If a specific SoC driver needs to change the
* default number of vectors, it needs to implement
--
2.20.1
next reply other threads:[~2019-02-27 16:52 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-27 16:52 Lucas Stach [this message]
2019-02-27 17:25 ` [PATCH] PCI: dwc: skip MSI init if MSIs have been explicitly disabled Fabio Estevam
2019-02-27 17:43 ` Tim Harvey
2019-02-28 13:29 ` Lorenzo Pieralisi
2019-03-01 10:10 ` Gustavo Pimentel
2019-03-01 12:29 ` Lorenzo Pieralisi
2019-03-04 19:25 ` Bjorn Helgaas
2019-03-04 19:39 ` Lucas Stach
2019-03-04 20:18 ` Marc Zyngier
2019-03-06 9:53 ` Gustavo Pimentel
2019-03-06 11:39 ` Lucas Stach
2019-03-06 15:59 ` Tim Harvey
2019-04-15 14:34 ` Gustavo Pimentel
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