On Thu, Dec 15, 2022 at 11:39:41PM -0800, Christoph Hellwig wrote: > On Fri, Dec 16, 2022 at 02:52:18AM +0300, Serge Semin wrote: > > Got it. Thanks for clarification. I'll resubmit the series with only > > the streaming DMA mask restoration. > > Note that even for that we need to make sure there are no outstanding > mappings when you change the mask. > What about instead of save/restore pattern I'll just change the dma_set_mask_and_coherent() method with the dma_set_coherent_mask() function call? It seems cleaner. Like this: < --- a/drivers/pci/controller/dwc/pcie-designware-host.c < +++ b/drivers/pci/controller/dwc/pcie-designware-host.c < @@ -366,10 +366,10 @@ 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)); < + 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"); < < msi_vaddr = dmam_alloc_coherent(dev, sizeof(u64), &pp->msi_data, < GFP_KERNEL); Thus the platform-specific streaming DMA mask would be preserved. Since it's PCIe then having the streaming DMA-mask less than 32-bits wide is very much improbable. Moreover DW PCIe AXI-interface can be synthesize only with one out of two address bus widths: 32 and 64. -Serge(y)
