| Message ID | 20240407-opp_support-v9-2-496184dc45d7@quicinc.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | PCI: qcom: Add support for OPP | expand |
On 4/7/2024 8:09 PM, Manivannan Sadhasivam wrote: > On Sun, Apr 07, 2024 at 10:07:35AM +0530, Krishna chaitanya chundru wrote: >> To access PCIe registers, PCIe BAR space, config space the CPU-PCIe > > Please specify whether you are referencing PCIe host controller or endpoint > device or both. > >> ICC (interconnect consumers) path should be voted otherwise it may > > ICC is just 'Interconnect' unless I misunderstood. > >> lead to NoC (Network on chip) timeout. We are surviving because of >> other driver vote for this path. >> > > s/vote/voting > >> As there is less access on this path compared to PCIe to mem path >> add minimum vote i.e 1KBps bandwidth always which is recommended >> by HW team. >> > > 'which is sufficient enough to keep the path active.' > >> When suspending, disable this path after register space access >> is done. >> >> Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> >> Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com> >> --- >> drivers/pci/controller/dwc/pcie-qcom.c | 38 ++++++++++++++++++++++++++++++---- >> 1 file changed, 34 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c >> index 14772edcf0d3..b4893214b2d3 100644 >> --- a/drivers/pci/controller/dwc/pcie-qcom.c >> +++ b/drivers/pci/controller/dwc/pcie-qcom.c >> @@ -245,6 +245,7 @@ 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; >> @@ -1409,6 +1410,9 @@ 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. >> @@ -1418,7 +1422,19 @@ 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 interconnect bandwidth for PCIe-MEM: %d\n", >> + ret); >> + return ret; >> + } >> + >> + /* >> + * Since the CPU-PCIe path is only used for activities like register > > Again, differentiate PCIe controller and endpoint device access. > Ack to all comments. I will modify in next patch. >> + * access, Config/BAR space access, HW team has recommended to use a >> + * minimal bandwidth of 1KBps just to keep the link active. >> + */ >> + ret = icc_set_bw(pcie->icc_cpu, 0, kBps_to_icc(1)); >> + if (ret) { >> + dev_err(pci->dev, "failed to set interconnect bandwidth for CPU-PCIe: %d\n", >> ret); >> return ret; >> } >> @@ -1448,7 +1464,7 @@ 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 interconnect bandwidth for PCIe-MEM: %d\n", >> ret); >> } >> } >> @@ -1610,7 +1626,7 @@ 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 interconnect bandwidth for PCIe-MEM: %d\n", ret); >> return ret; >> } >> >> @@ -1634,7 +1650,15 @@ static int qcom_pcie_suspend_noirq(struct device *dev) >> pcie->suspended = true; >> } >> >> - return 0; >> + /* >> + * Remove the vote for CPU-PCIe path now, since at this point onwards, >> + * no register access will be done. >> + */ > > Are you sure? Didn't we see late access to DBI registers on sc7280? > yeah you are correct I will add a check to disable icc only in suspend to idle case. only in suspend to ram case we see the DBI access in sc7280 -Krishna Chaitanya >> + ret = icc_disable(pcie->icc_cpu); >> + if (ret) >> + dev_err(dev, "failed to disable icc path of CPU-PCIe: %d\n", ret); > > s/failed to disable icc path/Failed to disable Interconnect path between CPU-PCIe > >> + >> + return ret; >> } >> >> static int qcom_pcie_resume_noirq(struct device *dev) >> @@ -1642,6 +1666,12 @@ static int qcom_pcie_resume_noirq(struct device *dev) >> struct qcom_pcie *pcie = dev_get_drvdata(dev); >> int ret; >> >> + ret = icc_enable(pcie->icc_cpu); >> + if (ret) { >> + dev_err(dev, "failed to enable icc path of CPU-PCIe: %d\n", ret); > > Same as above. > > - Mani >
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index 14772edcf0d3..b4893214b2d3 100644 --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -245,6 +245,7 @@ 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; @@ -1409,6 +1410,9 @@ 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. @@ -1418,7 +1422,19 @@ 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 interconnect bandwidth for PCIe-MEM: %d\n", + ret); + return ret; + } + + /* + * Since the CPU-PCIe path is only used for activities like register + * access, Config/BAR space access, HW team has recommended to use a + * minimal bandwidth of 1KBps just to keep the link active. + */ + ret = icc_set_bw(pcie->icc_cpu, 0, kBps_to_icc(1)); + if (ret) { + dev_err(pci->dev, "failed to set interconnect bandwidth for CPU-PCIe: %d\n", ret); return ret; } @@ -1448,7 +1464,7 @@ 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 interconnect bandwidth for PCIe-MEM: %d\n", ret); } } @@ -1610,7 +1626,7 @@ 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 interconnect bandwidth for PCIe-MEM: %d\n", ret); return ret; } @@ -1634,7 +1650,15 @@ static int qcom_pcie_suspend_noirq(struct device *dev) pcie->suspended = true; } - return 0; + /* + * Remove the vote for CPU-PCIe path now, since at this point onwards, + * no register access will be done. + */ + ret = icc_disable(pcie->icc_cpu); + if (ret) + dev_err(dev, "failed to disable icc path of CPU-PCIe: %d\n", ret); + + return ret; } static int qcom_pcie_resume_noirq(struct device *dev) @@ -1642,6 +1666,12 @@ static int qcom_pcie_resume_noirq(struct device *dev) struct qcom_pcie *pcie = dev_get_drvdata(dev); int ret; + ret = icc_enable(pcie->icc_cpu); + if (ret) { + dev_err(dev, "failed to enable icc path of CPU-PCIe: %d\n", ret); + return ret; + } + if (pcie->suspended) { ret = qcom_pcie_host_init(&pcie->pci->pp); if (ret)