Re: [PATCH] pci: designware: Set DMA_BYPASS bit in outbound IATU CTRL2 register
From: Sumit Kumar
Date: Tue Sep 08 2026 - 02:21:55 EST
On 9/2/2026 9:47 PM, Manivannan Sadhasivam wrote:
On Wed, Sep 02, 2026 at 08:44:57PM +0530, Krishna Chaitanya Chundru wrote:updated in v2.
This needs to be explained clearly in the commit message with an example
On 9/2/2026 7:37 PM, Manivannan Sadhasivam wrote:
On Wed, Aug 26, 2026 at 02:41:20PM +0530, Sumit Kumar wrote:issue happens, when host address(DMA destination address) matches with the
Outbound IATU apertures are configured with local device-side addresses.Why are you using the same device address in both DMA and iATU mapping? This
When DMA engine transactions use destination addresses which fall within
an outbound IATU aperture range, they get unintentionally translated by
the IATU, causing the wrong address to be sent on the PCIe link.
This results in data corruption or IOMMU errors at the host if the
translated address is not mapped.
sounds like a mapping problem that you should fix instead.
internal iova address programmed in iATU src address.
As we can cannot address in both, we need to program iATU in DMA bypass mode,
so DMA transcations will not go through iATU window.
matching the DWC terminologies such as 'Target Address Registers'.
- Mani
- Sumit