diff options
Diffstat (limited to 'drivers/pci/controller/dwc/pcie-designware-host.c')
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-designware-host.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index 3ab6ae3712c4..14f27985055e 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -366,7 +366,17 @@ static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp) dw_chained_msi_isr, pp); } - ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32)); + /* + * Even though the iMSI-RX Module supports 64-bit addresses some + * peripheral PCIe devices may lack 64-bit message support. In + * order not to miss MSI TLPs from those devices the MSI target + * address has to be within the lowest 4GB. + * + * Note until there is a better alternative found the reservation is + * done by allocating from the artificially limited DMA-coherent + * memory. + */ + ret = dma_set_coherent_mask(dev, DMA_BIT_MASK(32)); if (ret) dev_warn(dev, "Failed to set DMA mask to 32-bit. Devices with only 32-bit MSI support may not work properly\n"); |