[PATCH] ARM: imx6: Fix non-working MSI interrupts if PCIe switch is attached

[PATCH] ARM: imx6: Fix non-working MSI interrupts if PCIe switch is attached

[David Müller]

This problem has already been reported as 
https://bugzilla.kernel.org/show_bug.cgi?id=100051

Signed-off-by: David Müller <dave.mueller@gmx.ch>
---
 drivers/pci/host/pci-imx6.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
index c63691c..53f8dea 100644
--- a/drivers/pci/host/pci-imx6.c
+++ b/drivers/pci/host/pci-imx6.c
@@ -433,9 +433,6 @@ static void imx6_pcie_host_init(struct pcie_port *pp)
 	dw_pcie_setup_rc(pp);
 
 	imx6_pcie_start_link(pp);
-
-	if (IS_ENABLED(CONFIG_PCI_MSI))
-		dw_pcie_msi_init(pp);
 }
 
 static void imx6_pcie_reset_phy(struct pcie_port *pp)
@@ -550,6 +547,9 @@ static int __init imx6_add_pcie_port(struct pcie_port *pp,
 		return ret;
 	}
 
+	if (IS_ENABLED(CONFIG_PCI_MSI))
+		dw_pcie_msi_init(pp);
+
 	return 0;
 }
 
-- 
1.8.4

Re: [PATCH] ARM: imx6: Fix non-working MSI interrupts if PCIe switch is attached

[Lucas Stach]

Am Donnerstag, den 18.06.2015, 09:59 +0200 schrieb David Müller:
> This problem has already been reported as 
> https://bugzilla.kernel.org/show_bug.cgi?id=100051
> 

I need more explanation for this one. MSI interrupts were certainly
working fine even with a PCIe switchin between some time back. I think I
personally tested things with 3.19.

In the bug report you mention that the MSI_ADDR registers are
overwritten. Where does the write come from and why is it done?

Regards,
Lucas

> Signed-off-by: David Müller <dave.mueller@gmx.ch>
> ---
>  drivers/pci/host/pci-imx6.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
> index c63691c..53f8dea 100644
> --- a/drivers/pci/host/pci-imx6.c
> +++ b/drivers/pci/host/pci-imx6.c
> @@ -433,9 +433,6 @@ static void imx6_pcie_host_init(struct pcie_port *pp)
>  	dw_pcie_setup_rc(pp);
>  
>  	imx6_pcie_start_link(pp);
> -
> -	if (IS_ENABLED(CONFIG_PCI_MSI))
> -		dw_pcie_msi_init(pp);
>  }
>  
>  static void imx6_pcie_reset_phy(struct pcie_port *pp)
> @@ -550,6 +547,9 @@ static int __init imx6_add_pcie_port(struct pcie_port *pp,
>  		return ret;
>  	}
>  
> +	if (IS_ENABLED(CONFIG_PCI_MSI))
> +		dw_pcie_msi_init(pp);
> +
>  	return 0;
>  }
>  

-- 
Pengutronix e.K.             | Lucas Stach                 |
Industrial Linux Solutions   | http://www.pengutronix.de/  |

Re: [PATCH] ARM: imx6: Fix non-working MSI interrupts if PCIe switch is attached

[David Müller]

Lucas Stach wrote:
> I need more explanation for this one. MSI interrupts were certainly
> working fine even with a PCIe switchin between some time back. I think I
> personally tested things with 3.19.
> 
> In the bug report you mention that the MSI_ADDR registers are
> overwritten. Where does the write come from and why is it done?

I don't know. I just instrumented the driver with code to dump the
MSI_ADDR registers and noticed that they were programmed with the
correct value once, but at a later point in time, the value is gone.

Perhaps it's a some kind of partial HW reset of the PCIe host?

I'm working with a rev 1.2 silicon of the i.MX6Q.

Re: [PATCH] ARM: imx6: Fix non-working MSI interrupts if PCIe switch is attached

[Bjorn Helgaas]

On Thu, Jun 18, 2015 at 09:59:07AM +0200, David Müller wrote:
> This problem has already been reported as 
> https://bugzilla.kernel.org/show_bug.cgi?id=100051
> 
> Signed-off-by: David Müller <dave.mueller@gmx.ch>

Dropping for now, hoping for a repost with more info.

> ---
>  drivers/pci/host/pci-imx6.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
> index c63691c..53f8dea 100644
> --- a/drivers/pci/host/pci-imx6.c
> +++ b/drivers/pci/host/pci-imx6.c
> @@ -433,9 +433,6 @@ static void imx6_pcie_host_init(struct pcie_port *pp)
>  	dw_pcie_setup_rc(pp);
>  
>  	imx6_pcie_start_link(pp);
> -
> -	if (IS_ENABLED(CONFIG_PCI_MSI))
> -		dw_pcie_msi_init(pp);
>  }
>  
>  static void imx6_pcie_reset_phy(struct pcie_port *pp)
> @@ -550,6 +547,9 @@ static int __init imx6_add_pcie_port(struct pcie_port *pp,
>  		return ret;
>  	}
>  
> +	if (IS_ENABLED(CONFIG_PCI_MSI))
> +		dw_pcie_msi_init(pp);
> +
>  	return 0;
>  }
>  
> -- 
> 1.8.4
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html