From: Pali Rohár Date: Mon, 10 Jan 2022 01:50:07 +0000 (+0100) Subject: PCI: aardvark: Enable MSI-X support X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=754e449889b22fc3c34235e8836f08f51121d307;p=linux.git PCI: aardvark: Enable MSI-X support According to PCI 3.0 specification, sending both MSI and MSI-X interrupts is done by DWORD memory write operation to doorbell message address. The write operation for MSI has zero upper 16 bits and the MSI interrupt number in the lower 16 bits, while the write operation for MSI-X contains a 32-bit value from MSI-X table. Since the driver only uses interrupt numbers from range 0..31, the upper 16 bits of the DWORD memory write operation to doorbell message address are zero even for MSI-X interrupts. Thus we can enable MSI-X interrupts. Testing proves that kernel can correctly receive MSI-X interrupts from PCIe cards which supports both MSI and MSI-X interrupts. Link: https://lore.kernel.org/r/20220110015018.26359-13-kabel@kernel.org Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index b20973fae24db..45ff2a62e1a87 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -1335,7 +1335,7 @@ static struct irq_chip advk_msi_irq_chip = { static struct msi_domain_info advk_msi_domain_info = { .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | - MSI_FLAG_MULTI_PCI_MSI, + MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX, .chip = &advk_msi_irq_chip, };