Re: [PATCHv2 0/2] pci: fix msi_addr_mask on powerpc and sparc systems

[Madhavan Srinivasan <maddy@linux.ibm.com>]

On 2/27/26 10:14 PM, Bjorn Helgaas wrote:
> [cc->to powerpc, sparc maintainers for ack]
>
> On Fri, Feb 20, 2026 at 12:32:26PM +0530, Nilay Shroff wrote:
>> Hi,
>>
>> Recent changes [1] which replaced pci_dev::no_64bit_msi with pci_dev::
>> msi_addr_mask inadvertently missed to initialize the pci_dev::msi_addr_mask
>> to the DMA_BIT_MASK(64) on powerpc platform. Due to this, later the
>> validation the programmed MSI address against the msi_addr_mask fails.
>> This causes pci device probe method failures on powerpc platform. We also
>> realized that similar issue could potentially happen on sparc system as
>> well. So this series initializes pci_dev::msi_addr_mask to DMA_BIT_MASK(64)
>> when pci_dev is instantiated for both powerpc and sparc platforms.
>>
>> The first patch in the series fixes this on powerpc platform. The second
>> patch fixes this issue on sparc platform. Please note that as I don't have
>> access to the sparc platform, this patch was only compile tested on the
>> sparc system. Anyone from the community is welcome to test it who has
>> access to the sparc machine.
>>
>> [1] https://lore.kernel.org/all/20260129-pci-msi-addr-mask-v4-0-70da998f2750@iscas.ac.cn/
>>
>> Changes since v1:
>>    - Initialize the pci_dev:msi_addr_mask on sparc platform (Vivian Wang)
>>    - Some minor cosmetic fixes (Bjorn Helgaas)
>>
>> Nilay Shroff (2):
>>    powerpc/pci: Initialize msi_addr_mask for OF-created PCI devices
>>    sparc/pci: Initialize msi_addr_mask for OF-created PCI devices
>>
>>   arch/powerpc/kernel/pci_of_scan.c | 7 +++++++
>>   arch/sparc/kernel/pci.c           | 7 +++++++
>>   2 files changed, 14 insertions(+)
> These fix regressions on powerpc and sparc caused by 386ced19e9a3
> ("PCI/MSI: Convert the boolean no_64bit_msi flag to a DMA address
> mask").
>
> These fixes have been tested by Han Gao (SPARC Enterprise T5220),
> Nathaniel Roach (SPARC T5-2), and Venkat Rao Bagalkote (IBM Power
> System LPAR (pseries)).
>
> It'd be great to have acks from the powerpc and sparc folks so they
Sorry for the delayed response, yes we tested this from our end.
Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com>


> could be merged either by Thomas (who merged 386ced19e9a3) or me (via
> PCI tree).
>
> Bjorn
>