[PATCH v15 0/4] PCI: qcom: Add support for OPP

[PATCH v15 0/4] PCI: qcom: Add support for OPP

[Krishna chaitanya chundru]

This patch adds support for OPP to vote for the performance state of RPMH
power domain based upon PCIe speed it got enumerated.

QCOM Resource Power Manager-hardened (RPMh) is a hardware block which
maintains hardware state of a regulator by performing max aggregation of
the requests made by all of the processors.

PCIe controller can operate on different RPMh performance state of power
domain based up on the speed of the link. And this performance state varies
from target to target.

It is manadate to scale the performance state based up on the PCIe speed
link operates so that SoC can run under optimum power conditions.

Add Operating Performance Points(OPP) support to vote for RPMh state based
upon GEN speed link is operating.

Before link up PCIe driver will vote for the maximum performance state.

As now we are adding ICC BW vote in OPP, the ICC BW voting depends both
GEN speed and link width using opp-level to indicate the opp entry table
will be difficult.

In PCIe certain gen speeds like 2.5GT/s x2 & 5.0 GT/s X1 or 8.0 GT/s x2 &
16GT/s x1 use same ICC bw if we use freq in the OPP table to represent the
PCIe speed number of PCIe entries can reduced.

So going back to use freq in the OPP table instead of level.

To access PCIe registers of the host controller and endpoint PCIe
BAR space, config space the CPU-PCIe ICC (interconnect) path should
be voted otherwise it may lead to NoC (Network on chip) timeout.
We are surviving because of other driver voting for this path.

As there is less access on this path compared to PCIe to mem path
add minimum vote i.e 1KBps bandwidth always which is sufficient enough
to keep the path active and is recommended by HW team.

In suspend to ram case there can be some DBI access. Except in suspend
to ram case disable CPU-PCIe ICC path after register space access
is done.

Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
---
Changes from v14:
	- Couple of nits suggested by Ilpo Järvinen
	- Link to v14: https://lore.kernel.org/linux-arm-msm/20240609-opp_support-v14-0-801cff862b5a@quicinc.com/T/
Changes from v13:
	- Rebased the patch series on top of pci next.
	- Link to v13: https://lore.kernel.org/linux-arm-msm/20240518-opp_support-v13-0-78c73edf50de@quicinc.com/
Changes from v12:
	- removed icc bw of the memory path as suggested by mayank
	- Added check for icc_set_bw in the suspend path as suggested by mani.
	- Link to v12: https://lore.kernel.org/r/20240427-opp_support-v12-0-f6beb0a1f2fc@quicinc.com
Changes from v11:
	- added nicpicks suggested by mani.
	- Link to v11: https://lore.kernel.org/r/20240423-opp_support-v11-0-15fdd40b0f95@quicinc.com
Changes from v10:
	- Updated comments and logs as suggested by mani.
	- Link to v10: https://lore.kernel.org/r/20240409-opp_support-v10-0-1956e6be343f@quicinc.com
Changes from v9:
	- Disable interconnect CPU-PCIe path only system is not suspend to ram case.
	- If opp find freq fails in the probe fail the probe as suggested by mani.
	- Modify comments as suggested by mani
	- Link to v9: https://lore.kernel.org/r/20240407-opp_support-v9-0-496184dc45d7@quicinc.com
Changes from v8:
	- Removed the ack-by and reviewed by on dt-bindings as dt-bindings moved to new files.
	- Removed dt-binding patch for interconnects as it is added in the common file.
	- Added tags for interconnect as suggested by konrad
	- Added the comments as suggested by mani
	- In ICC BW vote for CPU to PCIe path if icc_disable() fails log error and return instead of re-init.
	- Link to v8: https://lore.kernel.org/linux-arm-msm/20240302-opp_support-v8-0-158285b86b10@quicinc.com/
Changes from v7:
	- Fix the compilation issue in patch3
	- Change the commit text and wrap the comments to 80 columns as suggested by bjorn
	- remove PCIE_MBS2FREQ macro as this is being used by only qcom drivers.
	- Link to v7: https://lore.kernel.org/r/20240223-opp_support-v7-0-10b4363d7e71@quicinc.com
Changes from v6:
	- change CPU-PCIe bandwidth to 1KBps as suggested by HW team.
	- Create a new API to get frequency based upon PCIe speed as suggested
	  by mani.
	- Updated few commit texts and comments.
	- Setting opp to NULL in suspend to remove any votes.
	- Link for v6: https://lore.kernel.org/linux-arm-msm/20240112-opp_support-v6-0-77bbf7d0cc37@quicinc.com/
Changes from v5:
	- Add ICC BW voting as part of OPP, rebase the latest kernel, and only
	- either OPP or ICC BW voting will supported we removed the patch to
	- return error for icc opp update patch.
	- As we added the icc bw voting in opp table I am not including reviewed
	- by tags given in previous patch.
	- Use opp freq to find opp entries as now we need to include pcie link
	- also in to considerations.
	- Add CPU-PCIe BW voting which is not present till now.
	- Drop  PCI: qcom: Return error from 'qcom_pcie_icc_update' as either opp or icc bw
	- only one executes and there is no need to fail if opp or icc update fails.
	- Link for v5: https://lore.kernel.org/linux-arm-msm/20231101063323.GH2897@thinkpad/T/
Changes from v4:
	- Added a separate patch for returning error from the qcom_pcie_upadate
	  and moved opp update logic to icc_update and used a bool variable to
	  update the opp.
	- Addressed comments made by pavan.
changes from v3:
	- Removing the opp vote on suspend when the link is not up and link is not
	  up and add debug prints as suggested by pavan.
	- Added dev_pm_opp_find_level_floor API to find the highest opp to vote.
changes from v2:
	- Instead of using the freq based opp search use level based as suggested
	  by Dmitry Baryshkov.
Changes from v1:
        - Addressed comments from Krzysztof Kozlowski.
        - Added the rpmhpd_opp_xxx phandle as suggested by pavan.
        - Added dev_pm_opp_set_opp API call which was missed on previous patch.
---

---
Krishna chaitanya chundru (4):
      PCI: qcom: Add ICC bandwidth vote for CPU to PCIe path
      dt-bindings: pci: qcom: Add OPP table
      PCI: Bring the PCIe speed to MBps logic to new pcie_dev_speed_mbps()
      PCI: qcom: Add OPP support to scale performance

 .../devicetree/bindings/pci/qcom,pcie-sm8450.yaml  |   4 +
 drivers/pci/controller/dwc/pcie-qcom.c             | 138 +++++++++++++++++----
 drivers/pci/pci.c                                  |  19 +--
 drivers/pci/pci.h                                  |  22 ++++
 4 files changed, 144 insertions(+), 39 deletions(-)
---
base-commit: 3bf9044d466637eaa28b87c4d6491dbfbe1b14ea
change-id: 20240618-opp_support-2a76c365c1d2

Best regards,
-- 
Krishna chaitanya chundru <quic_krichai@quicinc.com>

[PATCH v15 1/4] PCI: qcom: Add ICC bandwidth vote for CPU to PCIe path

[Krishna chaitanya chundru]

To access the host controller registers of the host controller and the
endpoint BAR/config space, the CPU-PCIe ICC (interconnect) path should
be voted otherwise it may lead to NoC (Network on chip) timeout.
We are surviving because of other driver voting for this path.

As there is less access on this path compared to PCIe to mem path
add minimum vote i.e 1KBps bandwidth always which is sufficient enough
to keep the path active and is recommended by HW team.

During S2RAM (Suspend-to-RAM), the DBI access can happen very late (while
disabling the boot CPU). So do not disable the CPU-PCIe interconnect path
during S2RAM as that may lead to NoC error.

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
---
 drivers/pci/controller/dwc/pcie-qcom.c | 45 +++++++++++++++++++++++++++++++---
 1 file changed, 41 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 5f9f0ff19baa..ff1d891c8b9a 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -253,6 +253,7 @@ struct qcom_pcie {
 	struct phy *phy;
 	struct gpio_desc *reset;
 	struct icc_path *icc_mem;
+	struct icc_path *icc_cpu;
 	const struct qcom_pcie_cfg *cfg;
 	struct dentry *debugfs;
 	bool suspended;
@@ -1369,6 +1370,9 @@ static int qcom_pcie_icc_init(struct qcom_pcie *pcie)
 	if (IS_ERR(pcie->icc_mem))
 		return PTR_ERR(pcie->icc_mem);
 
+	pcie->icc_cpu = devm_of_icc_get(pci->dev, "cpu-pcie");
+	if (IS_ERR(pcie->icc_cpu))
+		return PTR_ERR(pcie->icc_cpu);
 	/*
 	 * Some Qualcomm platforms require interconnect bandwidth constraints
 	 * to be set before enabling interconnect clocks.
@@ -1378,11 +1382,25 @@ static int qcom_pcie_icc_init(struct qcom_pcie *pcie)
 	 */
 	ret = icc_set_bw(pcie->icc_mem, 0, QCOM_PCIE_LINK_SPEED_TO_BW(1));
 	if (ret) {
-		dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
+		dev_err(pci->dev, "Failed to set bandwidth for PCIe-MEM interconnect path: %d\n",
 			ret);
 		return ret;
 	}
 
+	/*
+	 * Since the CPU-PCIe path is only used for activities like register
+	 * access of the host controller and endpoint Config/BAR space access,
+	 * HW team has recommended to use a minimal bandwidth of 1KBps just to
+	 * keep the path active.
+	 */
+	ret = icc_set_bw(pcie->icc_cpu, 0, kBps_to_icc(1));
+	if (ret) {
+		dev_err(pci->dev, "Failed to set bandwidth for CPU-PCIe interconnect path: %d\n",
+			ret);
+		icc_set_bw(pcie->icc_mem, 0, 0);
+		return ret;
+	}
+
 	return 0;
 }
 
@@ -1408,7 +1426,7 @@ static void qcom_pcie_icc_update(struct qcom_pcie *pcie)
 
 	ret = icc_set_bw(pcie->icc_mem, 0, width * QCOM_PCIE_LINK_SPEED_TO_BW(speed));
 	if (ret) {
-		dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
+		dev_err(pci->dev, "Failed to set bandwidth for PCIe-MEM interconnect path: %d\n",
 			ret);
 	}
 }
@@ -1570,7 +1588,7 @@ static int qcom_pcie_suspend_noirq(struct device *dev)
 	 */
 	ret = icc_set_bw(pcie->icc_mem, 0, kBps_to_icc(1));
 	if (ret) {
-		dev_err(dev, "Failed to set interconnect bandwidth: %d\n", ret);
+		dev_err(dev, "Failed to set bandwidth for PCIe-MEM interconnect path: %d\n", ret);
 		return ret;
 	}
 
@@ -1594,7 +1612,18 @@ static int qcom_pcie_suspend_noirq(struct device *dev)
 		pcie->suspended = true;
 	}
 
-	return 0;
+	/*
+	 * Only disable CPU-PCIe interconnect path if the suspend is non-S2RAM.
+	 * Because on some platforms, DBI access can happen very late during the
+	 * S2RAM and a non-active CPU-PCIe interconnect path may lead to NoC
+	 * error.
+	 */
+	if (pm_suspend_target_state != PM_SUSPEND_MEM) {
+		ret = icc_disable(pcie->icc_cpu);
+		if (ret)
+			dev_err(dev, "Failed to disable CPU-PCIe interconnect path: %d\n", ret);
+	}
+	return ret;
 }
 
 static int qcom_pcie_resume_noirq(struct device *dev)
@@ -1602,6 +1631,14 @@ static int qcom_pcie_resume_noirq(struct device *dev)
 	struct qcom_pcie *pcie = dev_get_drvdata(dev);
 	int ret;
 
+	if (pm_suspend_target_state != PM_SUSPEND_MEM) {
+		ret = icc_enable(pcie->icc_cpu);
+		if (ret) {
+			dev_err(dev, "Failed to enable CPU-PCIe interconnect path: %d\n", ret);
+			return ret;
+		}
+	}
+
 	if (pcie->suspended) {
 		ret = qcom_pcie_host_init(&pcie->pci->pp);
 		if (ret)

-- 
2.42.0

[PATCH v15 2/4] dt-bindings: pci: qcom: Add OPP table

[Krishna chaitanya chundru]

PCIe needs to choose the appropriate performance state of RPMh power
domain based on the PCIe gen speed.

Adding the Operating Performance Points table allows to adjust power
domain performance state and ICC peak bw, depending on the PCIe data
rate and link width.

Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
---
 Documentation/devicetree/bindings/pci/qcom,pcie-sm8450.yaml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/pci/qcom,pcie-sm8450.yaml b/Documentation/devicetree/bindings/pci/qcom,pcie-sm8450.yaml
index 1496d6993ab4..d8c0afaa4b19 100644
--- a/Documentation/devicetree/bindings/pci/qcom,pcie-sm8450.yaml
+++ b/Documentation/devicetree/bindings/pci/qcom,pcie-sm8450.yaml
@@ -69,6 +69,10 @@ properties:
       - const: msi6
       - const: msi7
 
+  operating-points-v2: true
+  opp-table:
+    type: object
+
   resets:
     maxItems: 1
 

-- 
2.42.0

Re: [PATCH v15 2/4] dt-bindings: pci: qcom: Add OPP table

[Krzysztof Wilczyński]

Hello,

> PCIe needs to choose the appropriate performance state of RPMh power
> domain based on the PCIe gen speed.
> 
> Adding the Operating Performance Points table allows to adjust power
> domain performance state and ICC peak bw, depending on the PCIe data
> rate and link width.

Applied to dt-bindings, thank you!

[1/1] dt-bindings: pci: qcom: Add OPP table
      https://git.kernel.org/pci/pci/c/1b029ce3b0b5

	Krzysztof

[PATCH v15 3/4] PCI: Bring the PCIe speed to MBps logic to new pcie_dev_speed_mbps()

[Krishna chaitanya chundru]

Bring the switch case in pcie_link_speed_mbps() to new function to
the header file so that it can be used in other places like
in controller driver.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
---
 drivers/pci/pci.c | 19 +------------------
 drivers/pci/pci.h | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index d2c388761ba9..5defa9384112 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -6027,24 +6027,7 @@ int pcie_link_speed_mbps(struct pci_dev *pdev)
 	if (err)
 		return err;
 
-	switch (to_pcie_link_speed(lnksta)) {
-	case PCIE_SPEED_2_5GT:
-		return 2500;
-	case PCIE_SPEED_5_0GT:
-		return 5000;
-	case PCIE_SPEED_8_0GT:
-		return 8000;
-	case PCIE_SPEED_16_0GT:
-		return 16000;
-	case PCIE_SPEED_32_0GT:
-		return 32000;
-	case PCIE_SPEED_64_0GT:
-		return 64000;
-	default:
-		break;
-	}
-
-	return -EINVAL;
+	return pcie_dev_speed_mbps(to_pcie_link_speed(lnksta));
 }
 EXPORT_SYMBOL(pcie_link_speed_mbps);
 
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 1b021579f26a..92dcc3702079 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -333,6 +333,28 @@ void pci_bus_put(struct pci_bus *bus);
 	 (speed) == PCIE_SPEED_2_5GT  ?  2500*8/10 : \
 	 0)
 
+static inline int pcie_dev_speed_mbps(enum pci_bus_speed speed)
+{
+	switch (speed) {
+	case PCIE_SPEED_2_5GT:
+		return 2500;
+	case PCIE_SPEED_5_0GT:
+		return 5000;
+	case PCIE_SPEED_8_0GT:
+		return 8000;
+	case PCIE_SPEED_16_0GT:
+		return 16000;
+	case PCIE_SPEED_32_0GT:
+		return 32000;
+	case PCIE_SPEED_64_0GT:
+		return 64000;
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
 const char *pci_speed_string(enum pci_bus_speed speed);
 enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev);
 enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev);

-- 
2.42.0

[PATCH v15 4/4] PCI: qcom: Add OPP support to scale performance

[Krishna chaitanya chundru]

QCOM Resource Power Manager-hardened (RPMh) is a hardware block which
maintains hardware state of a regulator by performing max aggregation of
the requests made by all of the clients.

PCIe controller can operate on different RPMh performance state of power
domain based on the speed of the link. And this performance state varies
from target to target, like some controllers support GEN3 in NOM (Nominal)
voltage corner, while some other supports GEN3 in low SVS (static voltage
scaling).

The SoC can be more power efficient if we scale the performance state
based on the aggregate PCIe link bandwidth.

Add Operating Performance Points (OPP) support to vote for RPMh state based
on the aggregate link bandwidth.

OPP can handle ICC bw voting also, so move ICC bw voting through OPP
framework if OPP entries are present.

As we are moving ICC voting as part of OPP, don't initialize ICC if OPP
is supported.

Before PCIe link is initialized vote for highest OPP in the OPP table,
so that we are voting for maximum voltage corner for the link to come up
in maximum supported speed.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
---
 drivers/pci/controller/dwc/pcie-qcom.c | 97 +++++++++++++++++++++++++++-------
 1 file changed, 78 insertions(+), 19 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index ff1d891c8b9a..26405fcfa499 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -18,9 +18,11 @@
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/kernel.h>
+#include <linux/limits.h>
 #include <linux/init.h>
 #include <linux/of.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>
@@ -29,6 +31,7 @@
 #include <linux/reset.h>
 #include <linux/slab.h>
 #include <linux/types.h>
+#include <linux/units.h>
 
 #include "../../pci.h"
 #include "pcie-designware.h"
@@ -1404,15 +1407,13 @@ static int qcom_pcie_icc_init(struct qcom_pcie *pcie)
 	return 0;
 }
 
-static void qcom_pcie_icc_update(struct qcom_pcie *pcie)
+static void qcom_pcie_icc_opp_update(struct qcom_pcie *pcie)
 {
+	u32 offset, status, width, speed;
 	struct dw_pcie *pci = pcie->pci;
-	u32 offset, status;
-	int speed, width;
-	int ret;
-
-	if (!pcie->icc_mem)
-		return;
+	unsigned long freq_kbps;
+	struct dev_pm_opp *opp;
+	int ret, freq_mbps;
 
 	offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
 	status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA);
@@ -1424,10 +1425,26 @@ static void qcom_pcie_icc_update(struct qcom_pcie *pcie)
 	speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status);
 	width = FIELD_GET(PCI_EXP_LNKSTA_NLW, status);
 
-	ret = icc_set_bw(pcie->icc_mem, 0, width * QCOM_PCIE_LINK_SPEED_TO_BW(speed));
-	if (ret) {
-		dev_err(pci->dev, "Failed to set bandwidth for PCIe-MEM interconnect path: %d\n",
-			ret);
+	if (pcie->icc_mem) {
+		ret = icc_set_bw(pcie->icc_mem, 0, width * QCOM_PCIE_LINK_SPEED_TO_BW(speed));
+		if (ret) {
+			dev_err(pci->dev, "Failed to set bandwidth for PCIe-MEM interconnect path: %d\n",
+				ret);
+		}
+	} else {
+		freq_mbps = pcie_dev_speed_mbps(pcie_link_speed[speed]);
+		if (freq_mbps < 0)
+			return;
+
+		freq_kbps = freq_mbps * KILO;
+		opp = dev_pm_opp_find_freq_exact(pci->dev, freq_kbps * width, true);
+		if (!IS_ERR(opp)) {
+			ret = dev_pm_opp_set_opp(pci->dev, opp);
+			if (ret)
+				dev_err(pci->dev, "Failed to set OPP for freq (%lu): %d\n",
+					freq_kbps * width, ret);
+		}
+		dev_pm_opp_put(opp);
 	}
 }
 
@@ -1471,7 +1488,9 @@ 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 = ULONG_MAX;
 	struct device *dev = &pdev->dev;
+	struct dev_pm_opp *opp;
 	struct qcom_pcie *pcie;
 	struct dw_pcie_rp *pp;
 	struct resource *res;
@@ -1539,9 +1558,42 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 		goto err_pm_runtime_put;
 	}
 
-	ret = qcom_pcie_icc_init(pcie);
-	if (ret)
+	/* OPP table is optional */
+	ret = devm_pm_opp_of_add_table(dev);
+	if (ret && ret != -ENODEV) {
+		dev_err_probe(dev, ret, "Failed to add OPP table\n");
 		goto err_pm_runtime_put;
+	}
+
+	/*
+	 * Before PCIe link is initialized vote for highest OPP in the OPP table,
+	 * so that we are voting for maximum voltage corner for the link to come up
+	 * in maximum supported speed. At the end of the probe(), OPP will be
+	 * updated using qcom_pcie_icc_opp_update().
+	 */
+	if (!ret) {
+		opp = dev_pm_opp_find_freq_floor(dev, &max_freq);
+		if (IS_ERR(opp)) {
+			dev_err_probe(pci->dev, PTR_ERR(opp),
+				      "Unable to find max freq OPP\n");
+			goto err_pm_runtime_put;
+		} else {
+			ret = dev_pm_opp_set_opp(dev, opp);
+		}
+
+		dev_pm_opp_put(opp);
+		if (ret) {
+			dev_err_probe(pci->dev, ret,
+				      "Failed to set OPP for freq %lu\n",
+				      max_freq);
+			goto err_pm_runtime_put;
+		}
+	} else {
+		/* Skip ICC init if OPP is supported as it is handled by OPP */
+		ret = qcom_pcie_icc_init(pcie);
+		if (ret)
+			goto err_pm_runtime_put;
+	}
 
 	ret = pcie->cfg->ops->get_resources(pcie);
 	if (ret)
@@ -1561,7 +1613,7 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 		goto err_phy_exit;
 	}
 
-	qcom_pcie_icc_update(pcie);
+	qcom_pcie_icc_opp_update(pcie);
 
 	if (pcie->mhi)
 		qcom_pcie_init_debugfs(pcie);
@@ -1586,10 +1638,14 @@ static int qcom_pcie_suspend_noirq(struct device *dev)
 	 * Set minimum bandwidth required to keep data path functional during
 	 * suspend.
 	 */
-	ret = icc_set_bw(pcie->icc_mem, 0, kBps_to_icc(1));
-	if (ret) {
-		dev_err(dev, "Failed to set bandwidth for PCIe-MEM interconnect path: %d\n", ret);
-		return ret;
+	if (pcie->icc_mem) {
+		ret = icc_set_bw(pcie->icc_mem, 0, kBps_to_icc(1));
+		if (ret) {
+			dev_err(dev,
+				"Failed to set bandwidth for PCIe-MEM interconnect path: %d\n",
+				ret);
+			return ret;
+		}
 	}
 
 	/*
@@ -1622,6 +1678,9 @@ static int qcom_pcie_suspend_noirq(struct device *dev)
 		ret = icc_disable(pcie->icc_cpu);
 		if (ret)
 			dev_err(dev, "Failed to disable CPU-PCIe interconnect path: %d\n", ret);
+
+		if (!pcie->icc_mem)
+			dev_pm_opp_set_opp(pcie->pci->dev, NULL);
 	}
 	return ret;
 }
@@ -1647,7 +1706,7 @@ static int qcom_pcie_resume_noirq(struct device *dev)
 		pcie->suspended = false;
 	}
 
-	qcom_pcie_icc_update(pcie);
+	qcom_pcie_icc_opp_update(pcie);
 
 	return 0;
 }

-- 
2.42.0

Re: [PATCH v15 0/4] PCI: qcom: Add support for OPP

[Krzysztof Wilczyński]

Hello,

> This patch adds support for OPP to vote for the performance state of RPMH
> power domain based upon PCIe speed it got enumerated.
> 
> QCOM Resource Power Manager-hardened (RPMh) is a hardware block which
> maintains hardware state of a regulator by performing max aggregation of
> the requests made by all of the processors.
> 
> PCIe controller can operate on different RPMh performance state of power
> domain based up on the speed of the link. And this performance state varies
> from target to target.
> 
> It is manadate to scale the performance state based up on the PCIe speed
> link operates so that SoC can run under optimum power conditions.
> 
> Add Operating Performance Points(OPP) support to vote for RPMh state based
> upon GEN speed link is operating.
> 
> Before link up PCIe driver will vote for the maximum performance state.
> 
> As now we are adding ICC BW vote in OPP, the ICC BW voting depends both
> GEN speed and link width using opp-level to indicate the opp entry table
> will be difficult.
> 
> In PCIe certain gen speeds like 2.5GT/s x2 & 5.0 GT/s X1 or 8.0 GT/s x2 &
> 16GT/s x1 use same ICC bw if we use freq in the OPP table to represent the
> PCIe speed number of PCIe entries can reduced.
> 
> So going back to use freq in the OPP table instead of level.
> 
> To access PCIe registers of the host controller and endpoint PCIe
> BAR space, config space the CPU-PCIe ICC (interconnect) path should
> be voted otherwise it may lead to NoC (Network on chip) timeout.
> We are surviving because of other driver voting for this path.
> 
> As there is less access on this path compared to PCIe to mem path
> add minimum vote i.e 1KBps bandwidth always which is sufficient enough
> to keep the path active and is recommended by HW team.
> 
> In suspend to ram case there can be some DBI access. Except in suspend
> to ram case disable CPU-PCIe ICC path after register space access
> is done.

Applied to controller/qcom, thank you!

[01/03] PCI: qcom: Add ICC bandwidth vote for CPU to PCIe path
        https://git.kernel.org/pci/pci/c/18f331d9c6db

[02/03] PCI: Bring the PCIe speed to MBps logic to new pcie_dev_speed_mbps()
        https://git.kernel.org/pci/pci/c/4bf3029dc2a1

[03/03] PCI: qcom: Add OPP support to scale performance
        https://git.kernel.org/pci/pci/c/78b5f6f8855e

	Krzysztof