9c63141025
The PCIe DWC host controller is now using MSI (Message-signaled-interrupts) by default. While ath9k itself does support MSI here, a lot of wlan adapters do not. Avoid non-functioning cards by simply continue to disable MSI for now. This can be done by appending "pci=nomsi" to the boot cmdline. Also an extra fix needs to be backported which avoids MSI initialization which prevented legacy IRQ's init from taking over. Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
49 lines
2.2 KiB
Diff
49 lines
2.2 KiB
Diff
From 26a3cdb73644090ff9a2fb68775ef61d361a8883 Mon Sep 17 00:00:00 2001
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From: Lucas Stach <l.stach@pengutronix.de>
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Date: Wed, 27 Feb 2019 17:52:19 +0100
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Subject: [PATCH] PCI: dwc: skip MSI init if MSIs have been explicitly disabled
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commit 3afc8299f39a27b60e1519a28e18878ce878e7dd upstream.
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Since 7c5925afbc58 (PCI: dwc: Move MSI IRQs allocation to IRQ domains
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hierarchical API) the MSI init claims one of the controller IRQs as a
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chained IRQ line for the MSI controller. On some designs, like the i.MX6,
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this line is shared with a PCIe legacy IRQ. When the line is claimed for
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the MSI domain, any device trying to use this legacy IRQs will fail to
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request this IRQ line.
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As MSI and legacy IRQs are already mutually exclusive on the DWC core,
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as the core won't forward any legacy IRQs once any MSI has been enabled,
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users wishing to use legacy IRQs already need to explictly disable MSI
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support (usually via the pci=nomsi kernel commandline option). To avoid
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any issues with MSI conflicting with legacy IRQs, just skip all of the
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DWC MSI initalization, including the IRQ line claim, when MSI is disabled.
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Fixes: 7c5925afbc58 ("PCI: dwc: Move MSI IRQs allocation to IRQ domains hierarchical API")
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Tested-by: Tim Harvey <tharvey@gateworks.com>
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Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
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Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Acked-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
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Cc: stable@vger.kernel.org
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Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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---
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drivers/pci/controller/dwc/pcie-designware-host.c | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
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index 0fa9e8fdce66..b56e22262a77 100644
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--- a/drivers/pci/controller/dwc/pcie-designware-host.c
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+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
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@@ -439,7 +439,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
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if (ret)
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pci->num_viewport = 2;
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- if (IS_ENABLED(CONFIG_PCI_MSI)) {
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+ if (IS_ENABLED(CONFIG_PCI_MSI) && pci_msi_enabled()) {
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/*
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* If a specific SoC driver needs to change the
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* default number of vectors, it needs to implement
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--
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2.17.1
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