[PATCH] PCI: tegra194: Fix broken tegra_pcie_ep_raise_msi_irq()

[PATCH] PCI: tegra194: Fix broken tegra_pcie_ep_raise_msi_irq()

[Niklas Cassel]

The pci_epc_raise_irq() supplies a MSI or MSI-X interrupt number in range
(1-N), see kdoc for pci_epc_raise_irq().

Thus, for MSI pci_epc_raise_irq() will supply interrupt number 1-32.

Convert the interrupt number to an MSI vector.

With this, the PCI endpoint kselftest test case MSI_TEST passes.

Also, set msi_capable to true, as the driver obviously supports MSI.
This helps pci_endpoint_test to use the optimal IRQ type when using
PCITEST_IRQ_TYPE_AUTO.

Signed-off-by: Niklas Cassel <cassel@kernel.org>
---
Note to PCI maintainers: this patch is made on top of
27fce9e8c6f0 ("PCI: endpoint: Drop superfluous pci_epc_features initialization")
which is currently queued on branch pci/endpoint.

 drivers/pci/controller/dwc/pcie-tegra194.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 0e413857649fd..fe418b9bfbb4b 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1955,10 +1955,10 @@ static int tegra_pcie_ep_raise_intx_irq(struct tegra_pcie_dw *pcie, u16 irq)
 
 static int tegra_pcie_ep_raise_msi_irq(struct tegra_pcie_dw *pcie, u16 irq)
 {
-	if (unlikely(irq > 31))
+	if (unlikely(irq > 32))
 		return -EINVAL;
 
-	appl_writel(pcie, BIT(irq), APPL_MSI_CTRL_1);
+	appl_writel(pcie, BIT(irq - 1), APPL_MSI_CTRL_1);
 
 	return 0;
 }
@@ -1998,6 +1998,7 @@ static int tegra_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
 
 static const struct pci_epc_features tegra_pcie_epc_features = {
 	.linkup_notifier = true,
+	.msi_capable = true,
 	.bar[BAR_0] = { .type = BAR_FIXED, .fixed_size = SZ_1M,
 			.only_64bit = true, },
 	.bar[BAR_1] = { .type = BAR_RESERVED, },
-- 
2.51.0

Re: [PATCH] PCI: tegra194: Fix broken tegra_pcie_ep_raise_msi_irq()

[Manivannan Sadhasivam]

On Fri, Sep 19, 2025 at 05:23:30PM +0200, Niklas Cassel wrote:
> The pci_epc_raise_irq() supplies a MSI or MSI-X interrupt number in range
> (1-N), see kdoc for pci_epc_raise_irq().
> 
> Thus, for MSI pci_epc_raise_irq() will supply interrupt number 1-32.
> 
> Convert the interrupt number to an MSI vector.
> 
> With this, the PCI endpoint kselftest test case MSI_TEST passes.
> 
> Also, set msi_capable to true, as the driver obviously supports MSI.
> This helps pci_endpoint_test to use the optimal IRQ type when using
> PCITEST_IRQ_TYPE_AUTO.
> 
> Signed-off-by: Niklas Cassel <cassel@kernel.org>

This is a bug fix. Hence, it deserves a Fixes tag and stable list should be
CCed for backporting.

- Mani

> ---
> Note to PCI maintainers: this patch is made on top of
> 27fce9e8c6f0 ("PCI: endpoint: Drop superfluous pci_epc_features initialization")
> which is currently queued on branch pci/endpoint.
> 
>  drivers/pci/controller/dwc/pcie-tegra194.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
> index 0e413857649fd..fe418b9bfbb4b 100644
> --- a/drivers/pci/controller/dwc/pcie-tegra194.c
> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
> @@ -1955,10 +1955,10 @@ static int tegra_pcie_ep_raise_intx_irq(struct tegra_pcie_dw *pcie, u16 irq)
>  
>  static int tegra_pcie_ep_raise_msi_irq(struct tegra_pcie_dw *pcie, u16 irq)
>  {
> -	if (unlikely(irq > 31))
> +	if (unlikely(irq > 32))
>  		return -EINVAL;
>  
> -	appl_writel(pcie, BIT(irq), APPL_MSI_CTRL_1);
> +	appl_writel(pcie, BIT(irq - 1), APPL_MSI_CTRL_1);
>  
>  	return 0;
>  }
> @@ -1998,6 +1998,7 @@ static int tegra_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
>  
>  static const struct pci_epc_features tegra_pcie_epc_features = {
>  	.linkup_notifier = true,
> +	.msi_capable = true,
>  	.bar[BAR_0] = { .type = BAR_FIXED, .fixed_size = SZ_1M,
>  			.only_64bit = true, },
>  	.bar[BAR_1] = { .type = BAR_RESERVED, },
> -- 
> 2.51.0
> 

-- 
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