Set DMA mask to 32-bit while allocating the MSI target address so that the address is usable for both 32-bit and 64-bit MSI capable devices. Throw a warning if it fails to set the mask to 32-bit to alert that devices that are only 32-bit MSI capable may not work properly. Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx> --- Given the other patch that I've pushed to the MSI sub-system http://patchwork.ozlabs.org/project/linux-pci/patch/20201117145728.4516-1-vidyas@xxxxxxxxxx/ which is going to catch any mismatch between MSI capability (32-bit) of the device and system's inability to allocate the required MSI target address, I'm not sure how much sense is this patch going to be make. But, I can certainly say that if the memory allocation mechanism gives the addresses from 64-bit pool by default, this patch at least makes sure that MSI target address is allocated from 32-bit pool. drivers/pci/controller/dwc/pcie-designware-host.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index 44c2a6572199..e6a230eddf66 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -388,6 +388,14 @@ int dw_pcie_host_init(struct pcie_port *pp) dw_chained_msi_isr, pp); + ret = dma_set_mask(pci->dev, DMA_BIT_MASK(32)); + if (!ret) { + dev_warn(pci->dev, + "Failed to set DMA mask to 32-bit. " + "Devices with only 32-bit MSI support" + " may not work properly\n"); + } + pp->msi_data = dma_map_single_attrs(pci->dev, &pp->msi_msg, sizeof(pp->msi_msg), DMA_FROM_DEVICE, -- 2.17.1
