Re: [PATCH v2] PCI: xilinx-xdma: Enable INTx interrupts

["Bandi, Ravi Kumar" <ravib@amazon.com>]

> On Oct 21, 2025, at 10:23 AM, Bjorn Helgaas <helgaas@kernel.org> wrote:
> 
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> 
> 
> 
> [+cc Stefan, Sean]
> 
> On Sat, Sep 20, 2025 at 10:52:32PM +0000, Ravi Kumar Bandi wrote:
>> The pcie-xilinx-dma-pl driver does not enable INTx interrupts
>> after initializing the port, preventing INTx interrupts from
>> PCIe endpoints from flowing through the Xilinx XDMA root port
>> bridge. This issue affects kernel 6.6.0 and later versions.
>> 
>> This patch allows INTx interrupts generated by PCIe endpoints
>> to flow through the root port. Tested the fix on a board with
>> two endpoints generating INTx interrupts. Interrupts are
>> properly detected and serviced. The /proc/interrupts output
>> shows:
>> 
>> [...]
>> 32:        320          0  pl_dma:RC-Event  16 Level     400000000.axi-pcie, azdrv
>> 52:        470          0  pl_dma:RC-Event  16 Level     500000000.axi-pcie, azdrv
>> [...]
>> 
>> Changes since v1::
>> - Fixed commit message per reviewer's comments
>> 
>> Fixes: 8d786149d78c ("PCI: xilinx-xdma: Add Xilinx XDMA Root Port driver")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Ravi Kumar Bandi <ravib@amazon.com>
> 
> Hi Ravi, obviously you tested this, but I don't know how to reconcile
> this with Stefan's INTx fix at
> https://lore.kernel.org/r/20251021154322.973640-1-stefan.roese@mailbox.org
> 
> Does Stefan's fix need to be squashed into this patch?

Hi Bjorn,

Sure, we can squash Stefan’s fix into this.

Thanks
Ravi

> 
>> ---
>> drivers/pci/controller/pcie-xilinx-dma-pl.c | 6 ++++++
>> 1 file changed, 6 insertions(+)
>> 
>> diff --git a/drivers/pci/controller/pcie-xilinx-dma-pl.c b/drivers/pci/controller/pcie-xilinx-dma-pl.c
>> index b037c8f315e4..cc539292d10a 100644
>> --- a/drivers/pci/controller/pcie-xilinx-dma-pl.c
>> +++ b/drivers/pci/controller/pcie-xilinx-dma-pl.c
>> @@ -659,6 +659,12 @@ static int xilinx_pl_dma_pcie_setup_irq(struct pl_dma_pcie *port)
>>              return err;
>>      }
>> 
>> +     /* Enable interrupts */
>> +     pcie_write(port, XILINX_PCIE_DMA_IMR_ALL_MASK,
>> +                XILINX_PCIE_DMA_REG_IMR);
>> +     pcie_write(port, XILINX_PCIE_DMA_IDRN_MASK,
>> +                XILINX_PCIE_DMA_REG_IDRN_MASK);
>> +
>>      return 0;
>> }
>> 
>> --
>> 2.47.3
>>