Re: [PATCH 1/2] PCI: rockchip: improve the deassert sequence of four reset pins

[Bjorn Helgaas <helgaas@kernel.org>]

On Fri, Sep 23, 2016 at 10:05:59AM +0800, Shawn Lin wrote:
> Per TRM, we need to deassert the four reset pins simultaneously.
> Currently the reset framework doesn't support that so we did it
> one by one. It seems no side effect found but it does impact the
> state machine of controller, so sometimes the change speed bit is
> not setted when sending training sequence from recover state.
> After the silicon RTL review from Soc guys, we don't need to do
> the sequence recommended by TRM, and could just move the deassert
> of mgmt_sticky_rst to the first place.
> 
> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>

Applied both to pci/host-rockchip for v4.9, thanks!

> ---
> 
>  drivers/pci/host/pcie-rockchip.c | 16 ++++++++++------
>  1 file changed, 10 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c
> index c3593e6..5e51121 100644
> --- a/drivers/pci/host/pcie-rockchip.c
> +++ b/drivers/pci/host/pcie-rockchip.c
> @@ -433,21 +433,25 @@ static int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
>  		return err;
>  	}
>  
> -	err = reset_control_deassert(rockchip->core_rst);
> +	/*
> +	 * Please don't reorder the deassert sequence of the following
> +	 * four reset pins.
> +	 */
> +	err = reset_control_deassert(rockchip->mgmt_sticky_rst);
>  	if (err) {
> -		dev_err(dev, "deassert core_rst err %d\n", err);
> +		dev_err(dev, "deassert mgmt_sticky_rst err %d\n", err);
>  		return err;
>  	}
>  
> -	err = reset_control_deassert(rockchip->mgmt_rst);
> +	err = reset_control_deassert(rockchip->core_rst);
>  	if (err) {
> -		dev_err(dev, "deassert mgmt_rst err %d\n", err);
> +		dev_err(dev, "deassert core_rst err %d\n", err);
>  		return err;
>  	}
>  
> -	err = reset_control_deassert(rockchip->mgmt_sticky_rst);
> +	err = reset_control_deassert(rockchip->mgmt_rst);
>  	if (err) {
> -		dev_err(dev, "deassert mgmt_sticky_rst err %d\n", err);
> +		dev_err(dev, "deassert mgmt_rst err %d\n", err);
>  		return err;
>  	}
>  
> -- 
> 2.3.7
> 
> 
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