Re: [PATCH v7 4/4] PCI: qcom: Switch pcie_1_pipe_clk_src after PHY init in SC7280

From: Bjorn Helgaas <helgaas@kernel.org>
To: Prasad Malisetty <pmaliset@codeaurora.org>
Cc: agross@kernel.org, bjorn.andersson@linaro.org,
	bhelgaas@google.com, robh+dt@kernel.org, swboyd@chromium.org,
	lorenzo.pieralisi@arm.com, svarbanov@mm-sol.com,
	devicetree@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	dianders@chromium.org, mka@chromium.org, vbadigan@codeaurora.org,
	sallenki@codeaurora.org, manivannan.sadhasivam@linaro.org
Subject: Re: [PATCH v7 4/4] PCI: qcom: Switch pcie_1_pipe_clk_src after PHY init in SC7280
Date: Tue, 14 Sep 2021 13:52:28 -0500	[thread overview]
Message-ID: <20210914185228.GA1443558@bjorn-Precision-5520> (raw)
In-Reply-To: <1631643550-29960-5-git-send-email-pmaliset@codeaurora.org>

On Tue, Sep 14, 2021 at 11:49:10PM +0530, Prasad Malisetty wrote:
> On the SC7280, the clock source for gcc_pcie_1_pipe_clk_src
> must be the TCXO while gdsc is enabled. After PHY init successful
> clock source should switch to pipe clock for gcc_pcie_1_pipe_clk_src.
> 
> Signed-off-by: Prasad Malisetty <pmaliset@codeaurora.org>
> ---
>  drivers/pci/controller/dwc/pcie-qcom.c | 90 +++++++++++++++++++++++++++++-----
>  1 file changed, 79 insertions(+), 11 deletions(-)
> 
> +struct qcom_pcie_cfg {
> +	const struct qcom_pcie_ops *ops;
> +	bool pcie_1_pipe_clk_src_switch;

This is OK, but all things being equal I like "unsigned int x:1" a
little better.  Here's some background:

  https://lore.kernel.org/r/CA+55aFzKQ6Pj18TB8p4Yr0M4t+S+BsiHH=BJNmn=76-NcjTj-g@mail.gmail.com/
  https://lore.kernel.org/r/CA+55aFxnePDimkVKVtv3gNmRGcwc8KQ5mHYvUxY8sAQg6yvVYg@mail.gmail.com/

> @@ -1467,6 +1531,7 @@ static int qcom_pcie_probe(struct platform_device *pdev)
>  	struct pcie_port *pp;
>  	struct dw_pcie *pci;
>  	struct qcom_pcie *pcie;
> +	const struct qcom_pcie_cfg *pcie_cfg = NULL;

No need to initialize this, since you always assign it before using
it.

>  	int ret;
>  
>  	pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
> @@ -1488,7 +1553,9 @@ static int qcom_pcie_probe(struct platform_device *pdev)
>  
>  	pcie->pci = pci;
>  
> -	pcie->ops = of_device_get_match_data(dev);
> +	pcie_cfg = of_device_get_match_data(dev);
> +	pcie->ops = pcie_cfg->ops;
> +	pcie->pcie_1_pipe_clk_src_switch = pcie_cfg->pcie_1_pipe_clk_src_switch;
>  
>  	pcie->reset = devm_gpiod_get_optional(dev, "perst", GPIOD_OUT_HIGH);
>  	if (IS_ERR(pcie->reset)) {

Looks good, thanks for working on this!