[v12,13/13] PCI: imx6: Disable clocks in reverse order of enable

From: Bjorn Helgaas <bhelgaas@google.com>

imx6_pcie_clk_enable() enables clocks in the order:

  pcie_phy
  pcie_bus
  pcie
  imx6_pcie_enable_ref_clk

Change imx6_pcie_clk_disable() to disable them in the reverse order.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
 drivers/pci/controller/dwc/pci-imx6.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

On Wed, Jun 15, 2022 at 06:15:51PM -0500, Bjorn Helgaas wrote:
> From: Bjorn Helgaas <bhelgaas@google.com>
> 
> imx6_pcie_clk_enable() enables clocks in the order:
> 
>   pcie_phy
>   pcie_bus
>   pcie
>   imx6_pcie_enable_ref_clk
> 
> Change imx6_pcie_clk_disable() to disable them in the reverse order.
> 
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> ---
>  drivers/pci/controller/dwc/pci-imx6.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index bd736aff94a3..738b5a732cef 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -655,10 +655,10 @@ static int imx6_pcie_clk_enable(struct imx6_pcie *imx6_pcie)
>  
>  static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
>  {
> -	clk_disable_unprepare(imx6_pcie->pcie);
> -	clk_disable_unprepare(imx6_pcie->pcie_phy);
> -	clk_disable_unprepare(imx6_pcie->pcie_bus);
>  	imx6_pcie_disable_ref_clk(imx6_pcie);
> +	clk_disable_unprepare(imx6_pcie->pcie);
> +	clk_disable_unprepare(imx6_pcie->pcie_bus);
> +	clk_disable_unprepare(imx6_pcie->pcie_phy);

Please comment on this.  I have no actual information that this is the
right thing, but normally we disable things in the reverse order that
we enabled them.

And the error path of imx6_pcie_deassert_core_reset() definitely
disables pcie, pcie_bus, pcie_phy in that order, so it seems
reasonable to do the same here.

>  }
>  
>  static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
> -- 
> 2.25.1
> 
> 
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> -----Original Message-----
> From: Bjorn Helgaas <helgaas@kernel.org>
> Sent: 2022年6月16日 7:16
> To: Hongxing Zhu <hongxing.zhu@nxp.com>; Lucas Stach
> <l.stach@pengutronix.de>; Rob Herring <robh+dt@kernel.org>; Mark Brown
> <broonie@kernel.org>; Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>; Fabio
> Estevam <festevam@gmail.com>; Francesco Dolcini
> <francesco.dolcini@toradex.com>
> Cc: linux-pci@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> linux-kernel@vger.kernel.org; kernel@pengutronix.de; dl-linux-imx
> <linux-imx@nxp.com>; Bjorn Helgaas <bhelgaas@google.com>
> Subject: [PATCH v12 13/13] PCI: imx6: Disable clocks in reverse order of enable
> 
> From: Bjorn Helgaas <bhelgaas@google.com>
> 
> imx6_pcie_clk_enable() enables clocks in the order:
> 
>   pcie_phy
>   pcie_bus
>   pcie
>   imx6_pcie_enable_ref_clk
> 
> Change imx6_pcie_clk_disable() to disable them in the reverse order.
> 
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Richard Zhu <hongxing.zhu@nxp.com>

Best Regards
Richard Zhu
> ---
>  drivers/pci/controller/dwc/pci-imx6.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c
> b/drivers/pci/controller/dwc/pci-imx6.c
> index bd736aff94a3..738b5a732cef 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -655,10 +655,10 @@ static int imx6_pcie_clk_enable(struct imx6_pcie
> *imx6_pcie)
> 
>  static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)  {
> -	clk_disable_unprepare(imx6_pcie->pcie);
> -	clk_disable_unprepare(imx6_pcie->pcie_phy);
> -	clk_disable_unprepare(imx6_pcie->pcie_bus);
>  	imx6_pcie_disable_ref_clk(imx6_pcie);
> +	clk_disable_unprepare(imx6_pcie->pcie);
> +	clk_disable_unprepare(imx6_pcie->pcie_bus);
> +	clk_disable_unprepare(imx6_pcie->pcie_phy);
>  }
> 
>  static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
> --
> 2.25.1