PCI: aardvark: Fix reading MSI interrupt number
authorPali Rohár <pali@kernel.org>
Mon, 10 Jan 2022 01:49:57 +0000 (02:49 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 8 Apr 2022 12:23:29 +0000 (14:23 +0200)
commit0fe94b84c43cfea867e1721606185e8686d7d32f
treed9909059609da359f68d4bd8efada3fb5873c9af
parent1f0add37ac5c3b6ede6cc58594c1d4942f7d46aa
PCI: aardvark: Fix reading MSI interrupt number

[ Upstream commit 805dfc18dd3d4dd97a987d4406593b5a225b1253 ]

In advk_pcie_handle_msi() it is expected that when bit i in the W1C
register PCIE_MSI_STATUS_REG is cleared, the PCIE_MSI_PAYLOAD_REG is
updated to contain the MSI number corresponding to index i.

Experiments show that this is not so, and instead PCIE_MSI_PAYLOAD_REG
always contains the number of the last received MSI, overall.

Do not read PCIE_MSI_PAYLOAD_REG register for determining MSI interrupt
number. Since Aardvark already forbids more than 32 interrupts and uses
own allocated hwirq numbers, the msi_idx already corresponds to the
received MSI number.

Link: https://lore.kernel.org/r/20220110015018.26359-3-kabel@kernel.org
Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/pci/controller/pci-aardvark.c