Re: [PATCH v1 3/3] PCI: qcom: Add OPP suuport for speed based performance state of RPMH

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 8/16/2023 11:54 AM, Pavan Kondeti wrote:
On Tue, Aug 15, 2023 at 05:56:48PM +0530, Krishna chaitanya chundru wrote:
Before link training vote for the maximum performance state of RPMH
and once the link is up, vote for the performance state based upon
the link speed.
Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
---
  drivers/pci/controller/dwc/pcie-qcom.c | 61 ++++++++++++++++++++++++++++++++++
  1 file changed, 61 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 7a87a47..e29a986 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -22,6 +22,7 @@
  #include <linux/of_device.h>
  #include <linux/of_gpio.h>
  #include <linux/pci.h>
+#include <linux/pm_opp.h>
  #include <linux/pm_runtime.h>
  #include <linux/platform_device.h>
  #include <linux/phy/pcie.h>
@@ -1357,6 +1358,51 @@ static int qcom_pcie_icc_init(struct qcom_pcie *pcie)
  	return 0;
  }
+static void qcom_pcie_opp_update(struct qcom_pcie *pcie)
+{
+	struct dw_pcie *pci = pcie->pci;
+	struct dev_pm_opp *opp;
+	u32 offset, status;
+	uint32_t freq;
+	int speed;
+	int ret = 0;
+
+	offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA);
+
+	/* Only update constraints if link is up. */
+	if (!(status & PCI_EXP_LNKSTA_DLLLA))
+		return;
+
+	speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status);
+
+	switch (speed) {
+	case 1:
+		freq = 2500000;
+		break;
+	case 2:
+		freq = 5000000;
+		break;
+	case 3:
+		freq = 8000000;
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		fallthrough;
+	case 4:
+		freq = 16000000;
+		break;
+	}
+
+	opp = dev_pm_opp_find_freq_exact(pci->dev, freq, true);
+
+	if (!IS_ERR(opp)) {
+		ret = dev_pm_opp_get_voltage(opp);
+		dev_pm_opp_put(opp);
+	}
+
Where are we setting the OPP here?

+}
+
  static void qcom_pcie_icc_update(struct qcom_pcie *pcie)
  {
  	struct dw_pcie *pci = pcie->pci;
@@ -1439,8 +1485,10 @@ static void qcom_pcie_init_debugfs(struct qcom_pcie *pcie)
  static int qcom_pcie_probe(struct platform_device *pdev)
  {
  	const struct qcom_pcie_cfg *pcie_cfg;
+	unsigned long max_freq = INT_MAX;
  	struct device *dev = &pdev->dev;
  	struct qcom_pcie *pcie;
+	struct dev_pm_opp *opp;
  	struct dw_pcie_rp *pp;
  	struct resource *res;
  	struct dw_pcie *pci;
@@ -1511,6 +1559,17 @@ static int qcom_pcie_probe(struct platform_device *pdev)
  	if (ret)
  		goto err_pm_runtime_put;
+ /* OPP table is optional */
+	ret = devm_pm_opp_of_add_table(dev);
+	if (ret && ret != -ENODEV) {
+		dev_err(dev, "Invalid OPP table in Device tree\n");
+		goto err_pm_runtime_put;
+	}
+
+	opp = dev_pm_opp_find_freq_floor(dev, &max_freq);
+	if (!IS_ERR(opp))
+		dev_pm_opp_put(opp);
+
This OPP (corresponding to max freq) is not used, so how are we voting
for max perf state during probe?

  	ret = pcie->cfg->ops->get_resources(pcie);
  	if (ret)
  		goto err_pm_runtime_put;
@@ -1531,6 +1590,8 @@ static int qcom_pcie_probe(struct platform_device *pdev)
qcom_pcie_icc_update(pcie); + qcom_pcie_opp_update(pcie);
+
commit description says, OPP voting is done as per the link speed after
probe? I don't see any calls to qcom_pcie_opp_update() outside probe.

my mistake dev_pm_opp_set_opp somehow missed here I will update in next patch.

- KC

  	if (pcie->mhi)
  		qcom_pcie_init_debugfs(pcie);
Thanks,
Pavan



[Index of Archives]     [DMA Engine]     [Linux Coverity]     [Linux USB]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Greybus]

  Powered by Linux