Received-SPF: pass (google.com: domain of linux-kernel+bounces-44180-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161;
Date: Tue, 30 Jan 2024 14:23:01 +0530
From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To: Mrinmay Sarkar <quic_msarkar@quicinc.com>
Cc: vkoul@kernel.org, jingoohan1@gmail.com, conor+dt@kernel.org,
	konrad.dybcio@linaro.org, robh+dt@kernel.org,
	quic_shazhuss@quicinc.com, quic_nitegupt@quicinc.com,
	quic_ramkri@quicinc.com, quic_nayiluri@quicinc.com,
	dmitry.baryshkov@linaro.org, quic_krichai@quicinc.com,
	quic_vbadigan@quicinc.com, quic_parass@quicinc.com,
	quic_schintav@quicinc.com, quic_shijjose@quicinc.com,
	Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
	Serge Semin <fancer.lancer@gmail.com>,
	Lorenzo Pieralisi <lpieralisi@kernel.org>,
	Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= <kw@linux.com>,
	Rob Herring <robh@kernel.org>, Bjorn Helgaas <bhelgaas@google.com>,
	Kishon Vijay Abraham I <kishon@kernel.org>,
	dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-pci@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	mhi@lists.linux.dev
Subject: Re: [PATCH v1 5/6] PCI: qcom-ep: Provide number of read/write
 channel for HDMA
Message-ID: <20240130085301.GB83288@thinkpad>
References: <1705669223-5655-1-git-send-email-quic_msarkar@quicinc.com>
 <1705669223-5655-6-git-send-email-quic_msarkar@quicinc.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <1705669223-5655-6-git-send-email-quic_msarkar@quicinc.com>

On Fri, Jan 19, 2024 at 06:30:21PM +0530, Mrinmay Sarkar wrote:
> There is no standard way to auto detect the number of available
> read/write channels in a platform. So adding this change to provide
> read/write channels count and also provide "EDMA_MF_HDMA_NATIVE"
> flag to support HDMA for 8775 platform.
> 
> 8775 has IP version 1.34.0 so intruduce a new cfg(cfg_1_34_0) for
> this platform. Add struct qcom_pcie_ep_cfg as match data. Assign
> hdma_supported flag into struct qcom_pcie_ep_cfg and set it true
> in cfg_1_34_0.
> 
> Signed-off-by: Mrinmay Sarkar <quic_msarkar@quicinc.com>
> ---
>  drivers/pci/controller/dwc/pcie-qcom-ep.c | 19 ++++++++++++++++++-
>  1 file changed, 18 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> index 45008e0..8d56435 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> @@ -149,6 +149,10 @@ enum qcom_pcie_ep_link_status {
>  	QCOM_PCIE_EP_LINK_DOWN,
>  };
>  

Add kdoc comment please as like the below struct.

> +struct qcom_pcie_ep_cfg {
> +	bool hdma_supported;
> +};
> +
>  /**
>   * struct qcom_pcie_ep - Qualcomm PCIe Endpoint Controller
>   * @pci: Designware PCIe controller struct
> @@ -167,6 +171,7 @@ enum qcom_pcie_ep_link_status {
>   * @num_clks: PCIe clocks count
>   * @perst_en: Flag for PERST enable
>   * @perst_sep_en: Flag for PERST separation enable
> + * @cfg: PCIe EP config struct
>   * @link_status: PCIe Link status
>   * @global_irq: Qualcomm PCIe specific Global IRQ
>   * @perst_irq: PERST# IRQ
> @@ -194,6 +199,7 @@ struct qcom_pcie_ep {
>  	u32 perst_en;
>  	u32 perst_sep_en;
>  
> +	const struct qcom_pcie_ep_cfg *cfg;
>  	enum qcom_pcie_ep_link_status link_status;
>  	int global_irq;
>  	int perst_irq;
> @@ -511,6 +517,10 @@ static void qcom_pcie_perst_assert(struct dw_pcie *pci)
>  	pcie_ep->link_status = QCOM_PCIE_EP_LINK_DISABLED;
>  }
>  
> +static const struct qcom_pcie_ep_cfg cfg_1_34_0 = {
> +	.hdma_supported = true,
> +};
> +
>  /* Common DWC controller ops */
>  static const struct dw_pcie_ops pci_ops = {
>  	.link_up = qcom_pcie_dw_link_up,
> @@ -816,6 +826,13 @@ static int qcom_pcie_ep_probe(struct platform_device *pdev)
>  	pcie_ep->pci.ops = &pci_ops;
>  	pcie_ep->pci.ep.ops = &pci_ep_ops;
>  	pcie_ep->pci.edma.nr_irqs = 1;
> +
> +	pcie_ep->cfg = of_device_get_match_data(dev);

Why do you want to cache "cfg" since it is only used in probe()?

> +	if (pcie_ep->cfg && pcie_ep->cfg->hdma_supported) {
> +		pcie_ep->pci.edma.ll_wr_cnt = 1;
> +		pcie_ep->pci.edma.ll_rd_cnt = 1;

Is the platform really has a single r/w channel?

- Mani

-- 
மணிவண்ணன் சதாசிவம்