diff options
Diffstat (limited to 'target/linux/generic/pending-5.15/850-0012-PCI-aardvark-Enable-MSI-X-support.patch')
| -rw-r--r-- | target/linux/generic/pending-5.15/850-0012-PCI-aardvark-Enable-MSI-X-support.patch | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/target/linux/generic/pending-5.15/850-0012-PCI-aardvark-Enable-MSI-X-support.patch b/target/linux/generic/pending-5.15/850-0012-PCI-aardvark-Enable-MSI-X-support.patch new file mode 100644 index 0000000000..20757c7a80 --- /dev/null +++ b/target/linux/generic/pending-5.15/850-0012-PCI-aardvark-Enable-MSI-X-support.patch @@ -0,0 +1,38 @@ +From 735a4ac9782b96fbe1543c578aa8334364f21abd Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org> +Date: Fri, 2 Apr 2021 14:05:24 +0200 +Subject: [PATCH] PCI: aardvark: Enable MSI-X support +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +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. + +Signed-off-by: Pali Rohár <pali@kernel.org> +Signed-off-by: Marek Behún <kabel@kernel.org> +--- + drivers/pci/controller/pci-aardvark.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +--- a/drivers/pci/controller/pci-aardvark.c ++++ b/drivers/pci/controller/pci-aardvark.c +@@ -1344,7 +1344,7 @@ 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, + }; + |