Re: [PATCH v8 1/5] PCI: dwc: ep: Clear MSI iATU mapping in dw_pcie_ep_cleanup()

[Niklas Cassel <cassel@kernel.org>]

On Mon, May 18, 2026 at 08:29:13PM +0530, Manivannan Sadhasivam via B4 Relay wrote:
> From: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
> 
> The MSI iATU mapping is currently only cleared when the endpoint is
> stopped via configfs or when the host updates the MSI address/size.
> This avoids redundant iATU reconfiguration every time the endpoint
> raises an MSI interrupt.
> 
> However, a fundamental reset triggered by PERST# assert/deassert
> resets all iATU inbound/outbound registers without going through the
> configfs stop path. If the host also retains the same MSI address/size
> after PERST# deassert, the driver never clears the stale MSI iATU
> mapping. It then continues using this stale mapping to raise the MSI
> interrupts, which can cause IOMMU faults and MSI failures on the host.
> 
> Fix this by clearing the MSI iATU mapping inside dw_pcie_ep_cleanup(),
> which is already called as part of the PERST# assert/deassert sequence.
> This unmaps the MSI iATU region and sets the msi_iatu_mapped flag to
> false, ensuring that dw_pcie_ep_raise_msi_irq() performs a fresh iATU
> mapping on its next invocation, regardless of whether the host changed
> the MSI address/size.
> 
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>

Doesn't this need a Fixes tag?


Side node: It seems like this series does no longer apply on pci/next.

Perhaps need to rebase and resend?


Kind regards,
Niklas