[PATCH] PCI: imx6: Fix link initialisation when the phy is ref clk provider

[Hongxing Zhu]

> -----Original Message-----
> From: Sascha Hauer <s.hauer at pengutronix.de>
> Sent: 2022Äê10ÔÂ12ÈÕ 21:27
> To: linux-pci at vger.kernel.org
> Cc: linux-arm-kernel at lists.infradead.org; Hongxing Zhu
> <hongxing.zhu at nxp.com>; Lorenzo Pieralisi <lpieralisi at kernel.org>;
> Pengutronix Kernel Team <kernel at pengutronix.de>; dl-linux-imx
> <linux-imx at nxp.com>; Rob Herring <robh at kernel.org>; Krzysztof Wilczy¨½ski
> <kw at linux.com>; Sascha Hauer <s.hauer at pengutronix.de>
> Subject: [PATCH] PCI: imx6: Fix link initialisation when the phy is ref clk
> provider
> 
> When the phy is the reference clock provider then it must be initialised and
> powered on before the reset on the client is deasserted, otherwise the link will
> never come up. The order was changed in cf236e0c0d59.
> Restore the correct order to make the driver work again on boards where the
> phy provides the reference clock.
> 
> Fixes: cf236e0c0d59 ("PCI: imx6: Do not hide PHY driver callbacks and refine
> the error handling")
> Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
Hi Sascha:
Thanks for your patch.
initialisation /s/ initialization
Initialised /s/ initialized

As I remember that the sequence of the initialization is not changed in
 cf236e0c0d59 ("PCI: imx6: Do not hide PHY driver callbacks and refine the error handling")
That commit just refactors the codes, and doesn't change the init-sequence.
Anyway, I had tested your patch on i.MX8MM and i.MX8MP EVK boards.
Both of these two boards works fine when the NVME device is inserted.

Tested-by: Richard Zhu <hongxing.zhu at nxp.com>

Best Regards
Richard Zhu
> ---
>  drivers/pci/controller/dwc/pci-imx6.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c
> b/drivers/pci/controller/dwc/pci-imx6.c
> index b5f0de455a7bd..211eb55d6d34b 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -942,12 +942,6 @@ static int imx6_pcie_host_init(struct dw_pcie_rp
> *pp)
>  		}
>  	}
> 
> -	ret = imx6_pcie_deassert_core_reset(imx6_pcie);
> -	if (ret < 0) {
> -		dev_err(dev, "pcie deassert core reset failed: %d\n", ret);
> -		goto err_phy_off;
> -	}
> -
>  	if (imx6_pcie->phy) {
>  		ret = phy_power_on(imx6_pcie->phy);
>  		if (ret) {
> @@ -955,6 +949,13 @@ static int imx6_pcie_host_init(struct dw_pcie_rp
> *pp)
>  			goto err_phy_off;
>  		}
>  	}
> +
> +	ret = imx6_pcie_deassert_core_reset(imx6_pcie);
> +	if (ret < 0) {
> +		dev_err(dev, "pcie deassert core reset failed: %d\n", ret);
> +		goto err_phy_off;
> +	}
> +
>  	imx6_setup_phy_mpll(imx6_pcie);
> 
>  	return 0;
> --
> 2.30.2