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[PATCH v3] PCI: imx6: Keep i.MX6Q Root Port MSI capability with iMSI-RX to work around hardware bug

hongxing.zhu@oss.nxp.com posted 1 patch 1 week, 1 day ago 
drivers/pci/controller/dwc/pci-imx6.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
[PATCH v3] PCI: imx6: Keep i.MX6Q Root Port MSI capability with iMSI-RX to work around hardware bug
Posted by hongxing.zhu@oss.nxp.com 1 week, 1 day ago 
From: Soeren Moch <smoch@web.de>

On some NXP chipsets, disabling Root Port MSI/MSI-X Capabilities blocks
MSIs originating from Endpoints from reaching the iMSI-RX controller.

To address this hardware bug, commit 3a4e8302e72f ("PCI: imx6: Keep Root
Port MSI capability with iMSI-RX to work around hardware bug") preserves
Root Port MSI and MSI-X Capabilities on i.MX7D, i.MX8MM, and i.MX8MQ
when iMSI-RX is in use.

The same applies to i.MX6Q, i.MX6QP and i.MX6SX. So preserve Root Port
MSI/MSI-X Capabilities there as well.

Note that preserving these Capabilities means Root Port-originated MSIs
such as AER and PME won't be received due to separate hardware limitations.
Users may need to use workarounds such as passing the 'pcie_pme=nomsi'
command-line parameter.

Fixes: f5cd8a929c825 ("PCI: dwc: Remove MSI/MSIX capability for Root Port if iMSI-RX is used as MSI controller")
Cc: <stable@vger.kernel.org> # 7.0+
Signed-off-by: Soeren Moch <smoch@web.de>
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Acked-by: Richard Zhu <hongxing.zhu@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
---
changes in v3:
- Extend the fix to i.MX6QP and i.MX6SX variants as well.
- Update the commit descriptions suggested by Bjorn.

changes in v2:
- collect a-b and r-b tags
- use correct fixes tag (Manivannan)
  (reference commit that introduced the bug, not the incomplete fix)
---
 drivers/pci/controller/dwc/pci-imx6.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 98e1db751132a..dba27eac6bff6 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -1995,7 +1995,8 @@ static const struct imx_pcie_drvdata drvdata[] = {
 		.flags = IMX_PCIE_FLAG_IMX_PHY |
 			 IMX_PCIE_FLAG_SPEED_CHANGE_WORKAROUND |
 			 IMX_PCIE_FLAG_BROKEN_SUSPEND |
-			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND,
+			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND |
+			 IMX_PCIE_FLAG_KEEP_MSI_CAP,
 		.dbi_length = 0x200,
 		.gpr = "fsl,imx6q-iomuxc-gpr",
 		.ltssm_off = IOMUXC_GPR12,
@@ -2011,7 +2012,8 @@ static const struct imx_pcie_drvdata drvdata[] = {
 		.flags = IMX_PCIE_FLAG_IMX_PHY |
 			 IMX_PCIE_FLAG_SPEED_CHANGE_WORKAROUND |
 			 IMX_PCIE_FLAG_SKIP_L23_READY |
-			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND,
+			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND |
+			 IMX_PCIE_FLAG_KEEP_MSI_CAP,
 		.gpr = "fsl,imx6q-iomuxc-gpr",
 		.ltssm_off = IOMUXC_GPR12,
 		.ltssm_mask = IMX6Q_GPR12_PCIE_CTL_2,
@@ -2026,7 +2028,8 @@ static const struct imx_pcie_drvdata drvdata[] = {
 		.flags = IMX_PCIE_FLAG_IMX_PHY |
 			 IMX_PCIE_FLAG_SPEED_CHANGE_WORKAROUND |
 			 IMX_PCIE_FLAG_SKIP_L23_READY |
-			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND,
+			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND |
+			 IMX_PCIE_FLAG_KEEP_MSI_CAP,
 		.dbi_length = 0x200,
 		.gpr = "fsl,imx6q-iomuxc-gpr",
 		.ltssm_off = IOMUXC_GPR12,
-- 
2.34.1
Re: [PATCH v3] PCI: imx6: Keep i.MX6Q Root Port MSI capability with iMSI-RX to work around hardware bug
Posted by Bjorn Helgaas 1 week ago 
On Fri, Jul 17, 2026 at 11:32:03AM +0800, hongxing.zhu@oss.nxp.com wrote:
> From: Soeren Moch <smoch@web.de>
> 
> On some NXP chipsets, disabling Root Port MSI/MSI-X Capabilities blocks
> MSIs originating from Endpoints from reaching the iMSI-RX controller.
> 
> To address this hardware bug, commit 3a4e8302e72f ("PCI: imx6: Keep Root
> Port MSI capability with iMSI-RX to work around hardware bug") preserves
> Root Port MSI and MSI-X Capabilities on i.MX7D, i.MX8MM, and i.MX8MQ
> when iMSI-RX is in use.
> 
> The same applies to i.MX6Q, i.MX6QP and i.MX6SX. So preserve Root Port
> MSI/MSI-X Capabilities there as well.
> 
> Note that preserving these Capabilities means Root Port-originated MSIs
> such as AER and PME won't be received due to separate hardware limitations.
> Users may need to use workarounds such as passing the 'pcie_pme=nomsi'
> command-line parameter.
> 
> Fixes: f5cd8a929c825 ("PCI: dwc: Remove MSI/MSIX capability for Root Port if iMSI-RX is used as MSI controller")
> Cc: <stable@vger.kernel.org> # 7.0+
> Signed-off-by: Soeren Moch <smoch@web.de>
> Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> Acked-by: Richard Zhu <hongxing.zhu@nxp.com>
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>

Applied to pci/for-linus for v7.2, thank you!

> ---
> changes in v3:
> - Extend the fix to i.MX6QP and i.MX6SX variants as well.
> - Update the commit descriptions suggested by Bjorn.
> 
> changes in v2:
> - collect a-b and r-b tags
> - use correct fixes tag (Manivannan)
>   (reference commit that introduced the bug, not the incomplete fix)
> ---
>  drivers/pci/controller/dwc/pci-imx6.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 98e1db751132a..dba27eac6bff6 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -1995,7 +1995,8 @@ static const struct imx_pcie_drvdata drvdata[] = {
>  		.flags = IMX_PCIE_FLAG_IMX_PHY |
>  			 IMX_PCIE_FLAG_SPEED_CHANGE_WORKAROUND |
>  			 IMX_PCIE_FLAG_BROKEN_SUSPEND |
> -			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND,
> +			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND |
> +			 IMX_PCIE_FLAG_KEEP_MSI_CAP,
>  		.dbi_length = 0x200,
>  		.gpr = "fsl,imx6q-iomuxc-gpr",
>  		.ltssm_off = IOMUXC_GPR12,
> @@ -2011,7 +2012,8 @@ static const struct imx_pcie_drvdata drvdata[] = {
>  		.flags = IMX_PCIE_FLAG_IMX_PHY |
>  			 IMX_PCIE_FLAG_SPEED_CHANGE_WORKAROUND |
>  			 IMX_PCIE_FLAG_SKIP_L23_READY |
> -			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND,
> +			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND |
> +			 IMX_PCIE_FLAG_KEEP_MSI_CAP,
>  		.gpr = "fsl,imx6q-iomuxc-gpr",
>  		.ltssm_off = IOMUXC_GPR12,
>  		.ltssm_mask = IMX6Q_GPR12_PCIE_CTL_2,
> @@ -2026,7 +2028,8 @@ static const struct imx_pcie_drvdata drvdata[] = {
>  		.flags = IMX_PCIE_FLAG_IMX_PHY |
>  			 IMX_PCIE_FLAG_SPEED_CHANGE_WORKAROUND |
>  			 IMX_PCIE_FLAG_SKIP_L23_READY |
> -			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND,
> +			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND |
> +			 IMX_PCIE_FLAG_KEEP_MSI_CAP,
>  		.dbi_length = 0x200,
>  		.gpr = "fsl,imx6q-iomuxc-gpr",
>  		.ltssm_off = IOMUXC_GPR12,
> -- 
> 2.34.1
>
Re: [PATCH v3] PCI: imx6: Keep i.MX6Q Root Port MSI capability with iMSI-RX to work around hardware bug
Posted by Soeren Moch 1 week ago 
On 17.07.26 05:32, hongxing.zhu@oss.nxp.com wrote:
> From: Soeren Moch <smoch@web.de>
>
> On some NXP chipsets, disabling Root Port MSI/MSI-X Capabilities blocks
> MSIs originating from Endpoints from reaching the iMSI-RX controller.
>
> To address this hardware bug, commit 3a4e8302e72f ("PCI: imx6: Keep Root
> Port MSI capability with iMSI-RX to work around hardware bug") preserves
> Root Port MSI and MSI-X Capabilities on i.MX7D, i.MX8MM, and i.MX8MQ
> when iMSI-RX is in use.
>
> The same applies to i.MX6Q, i.MX6QP and i.MX6SX. So preserve Root Port
> MSI/MSI-X Capabilities there as well.
>
> Note that preserving these Capabilities means Root Port-originated MSIs
> such as AER and PME won't be received due to separate hardware limitations.
> Users may need to use workarounds such as passing the 'pcie_pme=nomsi'
> command-line parameter.
>
> Fixes: f5cd8a929c825 ("PCI: dwc: Remove MSI/MSIX capability for Root Port if iMSI-RX is used as MSI controller")
> Cc: <stable@vger.kernel.org> # 7.0+
> Signed-off-by: Soeren Moch <smoch@web.de>
> Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> Acked-by: Richard Zhu <hongxing.zhu@nxp.com>
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
> ---
> changes in v3:
> - Extend the fix to i.MX6QP and i.MX6SX variants as well.
> - Update the commit descriptions suggested by Bjorn.
Thanks Richard for checking 6QP and 6SX platforms and extending the fix 
for them.

Soeren
>
> changes in v2:
> - collect a-b and r-b tags
> - use correct fixes tag (Manivannan)
>    (reference commit that introduced the bug, not the incomplete fix)
> ---
>   drivers/pci/controller/dwc/pci-imx6.c | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 98e1db751132a..dba27eac6bff6 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -1995,7 +1995,8 @@ static const struct imx_pcie_drvdata drvdata[] = {
>   		.flags = IMX_PCIE_FLAG_IMX_PHY |
>   			 IMX_PCIE_FLAG_SPEED_CHANGE_WORKAROUND |
>   			 IMX_PCIE_FLAG_BROKEN_SUSPEND |
> -			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND,
> +			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND |
> +			 IMX_PCIE_FLAG_KEEP_MSI_CAP,
>   		.dbi_length = 0x200,
>   		.gpr = "fsl,imx6q-iomuxc-gpr",
>   		.ltssm_off = IOMUXC_GPR12,
> @@ -2011,7 +2012,8 @@ static const struct imx_pcie_drvdata drvdata[] = {
>   		.flags = IMX_PCIE_FLAG_IMX_PHY |
>   			 IMX_PCIE_FLAG_SPEED_CHANGE_WORKAROUND |
>   			 IMX_PCIE_FLAG_SKIP_L23_READY |
> -			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND,
> +			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND |
> +			 IMX_PCIE_FLAG_KEEP_MSI_CAP,
>   		.gpr = "fsl,imx6q-iomuxc-gpr",
>   		.ltssm_off = IOMUXC_GPR12,
>   		.ltssm_mask = IMX6Q_GPR12_PCIE_CTL_2,
> @@ -2026,7 +2028,8 @@ static const struct imx_pcie_drvdata drvdata[] = {
>   		.flags = IMX_PCIE_FLAG_IMX_PHY |
>   			 IMX_PCIE_FLAG_SPEED_CHANGE_WORKAROUND |
>   			 IMX_PCIE_FLAG_SKIP_L23_READY |
> -			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND,
> +			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND |
> +			 IMX_PCIE_FLAG_KEEP_MSI_CAP,
>   		.dbi_length = 0x200,
>   		.gpr = "fsl,imx6q-iomuxc-gpr",
>   		.ltssm_off = IOMUXC_GPR12,

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