Re: [PATCH v2 2/8] PCI: qcom-ep: Add support for D-state change notification

[Manivannan Sadhasivam <mani@kernel.org>]

On Fri, Jun 30, 2023 at 04:22:05PM +0530, Krishna chaitanya chundru wrote:
> Add support to pass D-state change notification to Endpoint
> function driver.
> 
> Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>

Few comments below.

> ---
>  drivers/pci/controller/dwc/pcie-qcom-ep.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> index 1435f51..e75aec4 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> @@ -561,6 +561,7 @@ static irqreturn_t qcom_pcie_ep_global_irq_thread(int irq, void *data)
>  	struct device *dev = pci->dev;
>  	u32 status = readl_relaxed(pcie_ep->parf + PARF_INT_ALL_STATUS);
>  	u32 mask = readl_relaxed(pcie_ep->parf + PARF_INT_ALL_MASK);
> +	pci_power_t state;
>  	u32 dstate, val;
>  
>  	writel_relaxed(status, pcie_ep->parf + PARF_INT_ALL_CLEAR);
> @@ -583,11 +584,16 @@ static irqreturn_t qcom_pcie_ep_global_irq_thread(int irq, void *data)
>  		dstate = dw_pcie_readl_dbi(pci, DBI_CON_STATUS) &
>  					   DBI_CON_STATUS_POWER_STATE_MASK;
>  		dev_dbg(dev, "Received D%d state event\n", dstate);

We should also change this debug output to make use of pci_power_name() based on
the "state" variable and move it just above pci_epc_dstate_change(). But this
should be a separate patch.

> +		state = dstate;
>  		if (dstate == 3) {
>  			val = readl_relaxed(pcie_ep->parf + PARF_PM_CTRL);
>  			val |= PARF_PM_CTRL_REQ_EXIT_L1;
>  			writel_relaxed(val, pcie_ep->parf + PARF_PM_CTRL);
> +			state = PCI_D3hot;
> +			if (gpiod_get_value(pcie_ep->reset))
> +				state = PCI_D3cold;
>  		}
> +		pci_epc_dstate_change(pci->ep.epc, state);

Need to change this API as per my comment on patch 1.

- Mani

>  	} else if (FIELD_GET(PARF_INT_ALL_LINK_UP, status)) {
>  		dev_dbg(dev, "Received Linkup event. Enumeration complete!\n");
>  		dw_pcie_ep_linkup(&pci->ep);
> -- 
> 2.7.4
> 

-- 
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