linux-kernel - Re: [PATCH v2 04/12] PCI: brcmstb: Use swinit reset if available

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Message-ID: <efe5824c-3a05-4320-b8a1-85d22dbbf379@suse.de>
Date: Fri, 5 Jul 2024 11:23:15 +0300
From: Stanimir Varbanov <svarbanov@...e.de>
To: Jim Quinlan <james.quinlan@...adcom.com>, linux-pci@...r.kernel.org,
 Nicolas Saenz Julienne <nsaenz@...nel.org>,
 Bjorn Helgaas <bhelgaas@...gle.com>,
 Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
 Cyril Brulebois <kibi@...ian.org>, Stanimir Varbanov <svarbanov@...e.de>,
 bcm-kernel-feedback-list@...adcom.com, jim2101024@...il.com
Cc: Florian Fainelli <florian.fainelli@...adcom.com>,
 Lorenzo Pieralisi <lpieralisi@...nel.org>,
 Krzysztof Wilczyński <kw@...ux.com>,
 Rob Herring <robh@...nel.org>, Philipp Zabel <p.zabel@...gutronix.de>,
 "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE"
 <linux-rpi-kernel@...ts.infradead.org>,
 "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE"
 <linux-arm-kernel@...ts.infradead.org>,
 open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 04/12] PCI: brcmstb: Use swinit reset if available

Hi,

On 7/3/24 21:02, Jim Quinlan wrote:
> The 7712 SOC adds a software init reset device for the PCIe HW.
> If found in the DT node, use it.
> 
> Signed-off-by: Jim Quinlan <james.quinlan@...adcom.com>
> ---
>  drivers/pci/controller/pcie-brcmstb.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
> index 4104c3668fdb..69926ee5c961 100644
> --- a/drivers/pci/controller/pcie-brcmstb.c
> +++ b/drivers/pci/controller/pcie-brcmstb.c
> @@ -266,6 +266,7 @@ struct brcm_pcie {
>  	struct reset_control	*rescal;
>  	struct reset_control	*perst_reset;
>  	struct reset_control	*bridge;
> +	struct reset_control	*swinit;
>  	int			num_memc;
>  	u64			memc_size[PCIE_BRCM_MAX_MEMC];
>  	u32			hw_rev;
> @@ -1626,6 +1627,13 @@ static int brcm_pcie_probe(struct platform_device *pdev)
>  		dev_err(&pdev->dev, "could not enable clock\n");
>  		return ret;
>  	}
> +
> +	pcie->swinit = devm_reset_control_get_optional_exclusive(&pdev->dev, "swinit");
> +	if (IS_ERR(pcie->swinit)) {
> +		ret = dev_err_probe(&pdev->dev, PTR_ERR(pcie->swinit),
> +				    "failed to get 'swinit' reset\n");

Why "swinit" reset is special in this series? For example previous 3/12
patch which add "bridge" reset does not use dev_err_probe.

IMO you should use dev_err() here and below, and make a new follow-up
patch which change dev_err -> dev_err_probe on all places where getting
resources like resets and clocks.

> +		goto clk_out;
> +	}
>  	pcie->rescal = devm_reset_control_get_optional_shared(&pdev->dev, "rescal");
>  	if (IS_ERR(pcie->rescal)) {
>  		ret = PTR_ERR(pcie->rescal);
> @@ -1637,6 +1645,17 @@ static int brcm_pcie_probe(struct platform_device *pdev)
>  		goto clk_out;
>  	}
>  
> +	ret = reset_control_assert(pcie->swinit);
> +	if (ret) {
> +		dev_err_probe(&pdev->dev, ret, "could not assert reset 'swinit'\n");
> +		goto clk_out;

ditto

> +	}
> +	ret = reset_control_deassert(pcie->swinit);
> +	if (ret) {
> +		dev_err(&pdev->dev, "could not de-assert reset 'swinit' after asserting\n");
> +		goto clk_out;

this is fine

> +	}
> +
>  	ret = reset_control_reset(pcie->rescal);
>  	if (ret) {
>  		dev_err(&pdev->dev, "failed to deassert 'rescal'\n");

~Stan