[PATCH] PCI: qcom-ep: Set intx_capable in epc_features

[PATCH] PCI: qcom-ep: Set intx_capable in epc_features

[Niklas Cassel]

While I do not have the technical reference manuals, the qcom-ep
maintainer assures me that all compatibles support generating INTx IRQs.

Thus, set intx_capable to true in epc_features.

This will currently not have any effect, as PCITEST_IRQ_TYPE_AUTO will
always prefer MSI over INTx when both are available, however, perhaps the
supported irq_types in epc_features will be used for something else, e.g.
failing a ioctl(PCITEST_SET_IRQTYPE) with PCITEST_IRQ_TYPE_INTX, on the
host side, before ever configuring anything on the EP side. Thus, ensure
that epc_features represents reality.

Signed-off-by: Niklas Cassel <cassel@kernel.org>
---
 drivers/pci/controller/dwc/pcie-qcom-ep.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
index 46b1c6d19974..25468025e945 100644
--- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
+++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
@@ -824,6 +824,7 @@ static const struct pci_epc_features qcom_pcie_epc_features = {
 	.linkup_notifier = true,
 	.msi_capable = true,
 	.msix_capable = false,
+	.intx_capable = true,
 	.align = SZ_4K,
 	.bar[BAR_0] = { .only_64bit = true, },
 	.bar[BAR_1] = { .type = BAR_RESERVED, },
-- 
2.49.0

Re: [PATCH] PCI: qcom-ep: Set intx_capable in epc_features

[Dmitry Baryshkov]

On Wed, Apr 02, 2025 at 11:16:28AM +0200, Niklas Cassel wrote:
> While I do not have the technical reference manuals, the qcom-ep
> maintainer assures me that all compatibles support generating INTx IRQs.
> 
> Thus, set intx_capable to true in epc_features.
> 
> This will currently not have any effect, as PCITEST_IRQ_TYPE_AUTO will
> always prefer MSI over INTx when both are available, however, perhaps the
> supported irq_types in epc_features will be used for something else, e.g.
> failing a ioctl(PCITEST_SET_IRQTYPE) with PCITEST_IRQ_TYPE_INTX, on the
> host side, before ever configuring anything on the EP side. Thus, ensure
> that epc_features represents reality.
> 
> Signed-off-by: Niklas Cassel <cassel@kernel.org>
> ---
>  drivers/pci/controller/dwc/pcie-qcom-ep.c | 1 +
>  1 file changed, 1 insertion(+)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

-- 
With best wishes
Dmitry

Re: [PATCH] PCI: qcom-ep: Set intx_capable in epc_features

[Manivannan Sadhasivam]

On Wed, Apr 02, 2025 at 11:16:28AM +0200, Niklas Cassel wrote:
> While I do not have the technical reference manuals, the qcom-ep
> maintainer assures me that all compatibles support generating INTx IRQs.
> 

Yes, all Qcom EP controllers do support INTx.

> Thus, set intx_capable to true in epc_features.
> 

Hmm, this, I do not want to do atm. Qcom endpoints cannot raise INTx due to lack
of the driver support. So setting this flag would imply that the INTx is
functionally supported by the endpoint, but it is not.

Atleast, 'pci_epc_features' is not a devicetree configuration, that it has to
match what the hw supports instead of the driver support availability :)

- Mani

-- 
மணிவண்ணன் சதாசிவம்

Re: [PATCH] PCI: qcom-ep: Set intx_capable in epc_features

[Niklas Cassel]

On 2 April 2025 18:34:28 CEST, Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> wrote:
>On Wed, Apr 02, 2025 at 11:16:28AM +0200, Niklas Cassel wrote:
>> While I do not have the technical reference manuals, the qcom-ep
>> maintainer assures me that all compatibles support generating INTx IRQs.
>> 
>
>Yes, all Qcom EP controllers do support INTx.
>
>> Thus, set intx_capable to true in epc_features.
>> 
>
>Hmm, this, I do not want to do atm. Qcom endpoints cannot raise INTx due to lack
>of the driver support. So setting this flag would imply that the INTx is
>functionally supported by the endpoint, but it is not.
>
>Atleast, 'pci_epc_features' is not a devicetree configuration, that it has to
>match what the hw supports instead of the driver support availability :)

Ok, I misunderstood then.

Let's just drop this patch.



Kind regards,
Niklas