[PATCH v8 01/11] PCI: imx6: Fix establish link failure in EP mode for iMX8MM and iMX8MP

[Bjorn Helgaas]

On Mon, Jul 29, 2024 at 04:18:08PM -0400, Frank Li wrote:
> From: Richard Zhu <hongxing.zhu at nxp.com>
> 
> Add IMX6_PCIE_FLAG_HAS_APP_RESET flag to IMX8MM_EP and IMX8MP_EP drvdata.
> This flag was overlooked during code restructuring. It is crucial to
> release the app-reset from the System Reset Controller before initiating
> LTSSM to rectify the issue

What exactly is the issue?  What does it look like to a user?  The
endpoint doesn't establish a link correctly?

> Fixes: 0c9651c21f2a ("PCI: imx6: Simplify reset handling by using *_FLAG_HAS_*_RESET")
> Signed-off-by: Richard Zhu <hongxing.zhu at nxp.com>
> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>
> Signed-off-by: Frank Li <Frank.Li at nxp.com>

Does this need a -stable tag?

0c9651c21f2a appeared in v6.9, but this could arguably be v6.11
material if it fixes a serious issue.

> ---
>  drivers/pci/controller/dwc/pci-imx6.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 964d67756eb2b..42fd17fbadfa5 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -1562,7 +1562,8 @@ static const struct imx6_pcie_drvdata drvdata[] = {
>  	},
>  	[IMX8MM_EP] = {
>  		.variant = IMX8MM_EP,
> -		.flags = IMX6_PCIE_FLAG_HAS_PHYDRV,
> +		.flags = IMX6_PCIE_FLAG_HAS_APP_RESET |
> +			 IMX6_PCIE_FLAG_HAS_PHYDRV,
>  		.mode = DW_PCIE_EP_TYPE,
>  		.gpr = "fsl,imx8mm-iomuxc-gpr",
>  		.clk_names = imx8mm_clks,
> @@ -1573,7 +1574,8 @@ static const struct imx6_pcie_drvdata drvdata[] = {
>  	},
>  	[IMX8MP_EP] = {
>  		.variant = IMX8MP_EP,
> -		.flags = IMX6_PCIE_FLAG_HAS_PHYDRV,
> +		.flags = IMX6_PCIE_FLAG_HAS_APP_RESET |
> +			 IMX6_PCIE_FLAG_HAS_PHYDRV,
>  		.mode = DW_PCIE_EP_TYPE,
>  		.gpr = "fsl,imx8mp-iomuxc-gpr",
>  		.clk_names = imx8mm_clks,
> 
> -- 
> 2.34.1
>