Subject: [PATCH v5 3/3] PCI: qcom-ep: Add ICC bandwidth voting support

Add support to vote for ICC bandwidth based on the link
speed and width.

This patch is inspired from pcie-qcom driver to add basic
interconnect support.

Reference: commit c4860af88d0c ("PCI: qcom: Add basic interconnect
support").
Signed-off-by: Krishna chaitanya chundru <[email protected]>
---
drivers/pci/controller/dwc/pcie-qcom-ep.c | 73 +++++++++++++++++++++++++++++++
1 file changed, 73 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
index 1435f51..b613817 100644
--- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
+++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
@@ -13,6 +13,7 @@
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
+#include <linux/interconnect.h>
#include <linux/mfd/syscon.h>
#include <linux/phy/pcie.h>
#include <linux/phy/phy.h>
@@ -28,6 +29,7 @@
#define PARF_SYS_CTRL 0x00
#define PARF_DB_CTRL 0x10
#define PARF_PM_CTRL 0x20
+#define PARF_PM_STTS 0x24
#define PARF_MHI_CLOCK_RESET_CTRL 0x174
#define PARF_MHI_BASE_ADDR_LOWER 0x178
#define PARF_MHI_BASE_ADDR_UPPER 0x17c
@@ -128,11 +130,19 @@
/* DBI register fields */
#define DBI_CON_STATUS_POWER_STATE_MASK GENMASK(1, 0)

+#define DBI_LINKCTRLSTATUS 0x80
+#define DBI_LINKCTRLSTATUS_SHIFT 16
+
#define XMLH_LINK_UP 0x400
#define CORE_RESET_TIME_US_MIN 1000
#define CORE_RESET_TIME_US_MAX 1005
#define WAKE_DELAY_US 2000 /* 2 ms */

+#define PCIE_GEN1_BW_MBPS 250
+#define PCIE_GEN2_BW_MBPS 500
+#define PCIE_GEN3_BW_MBPS 985
+#define PCIE_GEN4_BW_MBPS 1969
+
#define to_pcie_ep(x) dev_get_drvdata((x)->dev)

enum qcom_pcie_ep_link_status {
@@ -178,6 +188,8 @@ struct qcom_pcie_ep {
struct phy *phy;
struct dentry *debugfs;

+ struct icc_path *icc_mem;
+
struct clk_bulk_data *clks;
int num_clks;

@@ -253,9 +265,51 @@ static void qcom_pcie_dw_stop_link(struct dw_pcie *pci)
disable_irq(pcie_ep->perst_irq);
}

+static void qcom_pcie_ep_icc_update(struct qcom_pcie_ep *pcie_ep)
+{
+ struct dw_pcie *pci = &pcie_ep->pci;
+ u32 offset, status, bw;
+ int speed, width;
+ int ret;
+
+ if (!pcie_ep->icc_mem)
+ return;
+
+ offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+ status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA);
+
+ speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status);
+ width = FIELD_GET(PCI_EXP_LNKSTA_NLW, status);
+
+ switch (speed) {
+ case 1:
+ bw = MBps_to_icc(PCIE_GEN1_BW_MBPS);
+ break;
+ case 2:
+ bw = MBps_to_icc(PCIE_GEN2_BW_MBPS);
+ break;
+ case 3:
+ bw = MBps_to_icc(PCIE_GEN3_BW_MBPS);
+ break;
+ default:
+ dev_warn(pci->dev, "using default GEN4 bandwidth\n");
+ fallthrough;
+ case 4:
+ bw = MBps_to_icc(PCIE_GEN4_BW_MBPS);
+ break;
+ }
+
+ ret = icc_set_bw(pcie_ep->icc_mem, 0, width * bw);
+ if (ret) {
+ dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
+ ret);
+ }
+}
+
static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep)
{
int ret;
+ struct dw_pcie *pci = &pcie_ep->pci;

ret = clk_bulk_prepare_enable(pcie_ep->num_clks, pcie_ep->clks);
if (ret)
@@ -277,6 +331,20 @@ static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep)
if (ret)
goto err_phy_exit;

+ /*
+ * Some Qualcomm platforms require interconnect bandwidth constraints
+ * to be set before enabling interconnect clocks.
+ *
+ * Set an initial peak bandwidth corresponding to single-lane Gen 1
+ * for the pcie-mem path.
+ */
+ ret = icc_set_bw(pcie_ep->icc_mem, 0, MBps_to_icc(PCIE_GEN1_BW_MBPS));
+ if (ret) {
+ dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
+ ret);
+ goto err_phy_exit;
+ }
+
return 0;

err_phy_exit:
@@ -550,6 +618,10 @@ static int qcom_pcie_ep_get_resources(struct platform_device *pdev,
if (IS_ERR(pcie_ep->phy))
ret = PTR_ERR(pcie_ep->phy);

+ pcie_ep->icc_mem = devm_of_icc_get(dev, "pcie-mem");
+ if (IS_ERR(pcie_ep->icc_mem))
+ ret = PTR_ERR(pcie_ep->icc_mem);
+
return ret;
}

@@ -573,6 +645,7 @@ static irqreturn_t qcom_pcie_ep_global_irq_thread(int irq, void *data)
} else if (FIELD_GET(PARF_INT_ALL_BME, status)) {
dev_dbg(dev, "Received BME event. Link is enabled!\n");
pcie_ep->link_status = QCOM_PCIE_EP_LINK_ENABLED;
+ qcom_pcie_ep_icc_update(pcie_ep);
pci_epc_bme_notify(pci->ep.epc);
} else if (FIELD_GET(PARF_INT_ALL_PM_TURNOFF, status)) {
dev_dbg(dev, "Received PM Turn-off event! Entering L23\n");
--
2.7.4



2023-06-27 06:51:56

by Pavan Kondeti

[permalink] [raw]
Subject: Re: [PATCH v5 3/3] PCI: qcom-ep: Add ICC bandwidth voting support

On Tue, Jun 27, 2023 at 06:31:31AM +0530, Krishna chaitanya chundru wrote:
> +static void qcom_pcie_ep_icc_update(struct qcom_pcie_ep *pcie_ep)
> +{
> + struct dw_pcie *pci = &pcie_ep->pci;
> + u32 offset, status, bw;
> + int speed, width;
> + int ret;
> +
> + if (!pcie_ep->icc_mem)
> + return;
> +

Is this check needed? interconnect is added as required property and
probe is failed if interconnect get fails. qcom_pcie_enable_resources()
which gets called before enabling this interrupt is assuming that
interconnect available.


> + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
> + status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA);
> +
> + speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status);
> + width = FIELD_GET(PCI_EXP_LNKSTA_NLW, status);
> +
> + switch (speed) {
> + case 1:
> + bw = MBps_to_icc(PCIE_GEN1_BW_MBPS);
> + break;
> + case 2:
> + bw = MBps_to_icc(PCIE_GEN2_BW_MBPS);
> + break;
> + case 3:
> + bw = MBps_to_icc(PCIE_GEN3_BW_MBPS);
> + break;
> + default:
> + dev_warn(pci->dev, "using default GEN4 bandwidth\n");
> + fallthrough;
> + case 4:
> + bw = MBps_to_icc(PCIE_GEN4_BW_MBPS);
> + break;
> + }
> +
> + ret = icc_set_bw(pcie_ep->icc_mem, 0, width * bw);
> + if (ret) {
> + dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
> + ret);
> + }

Are you not seeing the below warning from checkpatch?

WARNING: braces {} are not necessary for single statement blocks

> +}
> +
> static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep)
> {
> int ret;
> + struct dw_pcie *pci = &pcie_ep->pci;
>
> ret = clk_bulk_prepare_enable(pcie_ep->num_clks, pcie_ep->clks);
> if (ret)
> @@ -277,6 +331,20 @@ static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep)
> if (ret)
> goto err_phy_exit;
>
> + /*
> + * Some Qualcomm platforms require interconnect bandwidth constraints
> + * to be set before enabling interconnect clocks.
> + *
> + * Set an initial peak bandwidth corresponding to single-lane Gen 1
> + * for the pcie-mem path.
> + */
> + ret = icc_set_bw(pcie_ep->icc_mem, 0, MBps_to_icc(PCIE_GEN1_BW_MBPS));
> + if (ret) {
> + dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
> + ret);
> + goto err_phy_exit;
> + }
> +
> return 0;

Thanks,
Pavan

2023-06-27 15:36:23

by Manivannan Sadhasivam

[permalink] [raw]
Subject: Re: [PATCH v5 3/3] PCI: qcom-ep: Add ICC bandwidth voting support

On Tue, Jun 27, 2023 at 06:31:31AM +0530, Krishna chaitanya chundru wrote:
> Add support to vote for ICC bandwidth based on the link
> speed and width.
>
> This patch is inspired from pcie-qcom driver to add basic
> interconnect support.
>
> Reference: commit c4860af88d0c ("PCI: qcom: Add basic interconnect
> support").
> Signed-off-by: Krishna chaitanya chundru <[email protected]>
> ---
> drivers/pci/controller/dwc/pcie-qcom-ep.c | 73 +++++++++++++++++++++++++++++++
> 1 file changed, 73 insertions(+)
>
> diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> index 1435f51..b613817 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> @@ -13,6 +13,7 @@
> #include <linux/debugfs.h>
> #include <linux/delay.h>
> #include <linux/gpio/consumer.h>
> +#include <linux/interconnect.h>
> #include <linux/mfd/syscon.h>
> #include <linux/phy/pcie.h>
> #include <linux/phy/phy.h>
> @@ -28,6 +29,7 @@
> #define PARF_SYS_CTRL 0x00
> #define PARF_DB_CTRL 0x10
> #define PARF_PM_CTRL 0x20
> +#define PARF_PM_STTS 0x24
> #define PARF_MHI_CLOCK_RESET_CTRL 0x174
> #define PARF_MHI_BASE_ADDR_LOWER 0x178
> #define PARF_MHI_BASE_ADDR_UPPER 0x17c
> @@ -128,11 +130,19 @@
> /* DBI register fields */
> #define DBI_CON_STATUS_POWER_STATE_MASK GENMASK(1, 0)
>
> +#define DBI_LINKCTRLSTATUS 0x80
> +#define DBI_LINKCTRLSTATUS_SHIFT 16

not used?

> +
> #define XMLH_LINK_UP 0x400
> #define CORE_RESET_TIME_US_MIN 1000
> #define CORE_RESET_TIME_US_MAX 1005
> #define WAKE_DELAY_US 2000 /* 2 ms */
>
> +#define PCIE_GEN1_BW_MBPS 250
> +#define PCIE_GEN2_BW_MBPS 500
> +#define PCIE_GEN3_BW_MBPS 985
> +#define PCIE_GEN4_BW_MBPS 1969
> +
> #define to_pcie_ep(x) dev_get_drvdata((x)->dev)
>
> enum qcom_pcie_ep_link_status {
> @@ -178,6 +188,8 @@ struct qcom_pcie_ep {
> struct phy *phy;
> struct dentry *debugfs;
>
> + struct icc_path *icc_mem;
> +
> struct clk_bulk_data *clks;
> int num_clks;
>
> @@ -253,9 +265,51 @@ static void qcom_pcie_dw_stop_link(struct dw_pcie *pci)
> disable_irq(pcie_ep->perst_irq);
> }
>
> +static void qcom_pcie_ep_icc_update(struct qcom_pcie_ep *pcie_ep)
> +{
> + struct dw_pcie *pci = &pcie_ep->pci;
> + u32 offset, status, bw;
> + int speed, width;
> + int ret;
> +
> + if (!pcie_ep->icc_mem)
> + return;
> +
> + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
> + status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA);
> +
> + speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status);
> + width = FIELD_GET(PCI_EXP_LNKSTA_NLW, status);
> +
> + switch (speed) {
> + case 1:
> + bw = MBps_to_icc(PCIE_GEN1_BW_MBPS);
> + break;
> + case 2:
> + bw = MBps_to_icc(PCIE_GEN2_BW_MBPS);
> + break;
> + case 3:
> + bw = MBps_to_icc(PCIE_GEN3_BW_MBPS);
> + break;
> + default:
> + dev_warn(pci->dev, "using default GEN4 bandwidth\n");
> + fallthrough;
> + case 4:
> + bw = MBps_to_icc(PCIE_GEN4_BW_MBPS);
> + break;
> + }
> +
> + ret = icc_set_bw(pcie_ep->icc_mem, 0, width * bw);
> + if (ret) {
> + dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
> + ret);

No need of braces for single line.

> + }
> +}
> +
> static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep)
> {
> int ret;
> + struct dw_pcie *pci = &pcie_ep->pci;
>
> ret = clk_bulk_prepare_enable(pcie_ep->num_clks, pcie_ep->clks);
> if (ret)
> @@ -277,6 +331,20 @@ static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep)
> if (ret)
> goto err_phy_exit;
>
> + /*
> + * Some Qualcomm platforms require interconnect bandwidth constraints
> + * to be set before enabling interconnect clocks.
> + *
> + * Set an initial peak bandwidth corresponding to single-lane Gen 1
> + * for the pcie-mem path.
> + */
> + ret = icc_set_bw(pcie_ep->icc_mem, 0, MBps_to_icc(PCIE_GEN1_BW_MBPS));
> + if (ret) {
> + dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
> + ret);
> + goto err_phy_exit;

Again, you should power off the PHY in the case of error. err_phy_exit is not
doing that for you.

- Mani

> + }
> +
> return 0;
>
> err_phy_exit:
> @@ -550,6 +618,10 @@ static int qcom_pcie_ep_get_resources(struct platform_device *pdev,
> if (IS_ERR(pcie_ep->phy))
> ret = PTR_ERR(pcie_ep->phy);
>
> + pcie_ep->icc_mem = devm_of_icc_get(dev, "pcie-mem");
> + if (IS_ERR(pcie_ep->icc_mem))
> + ret = PTR_ERR(pcie_ep->icc_mem);
> +
> return ret;
> }
>
> @@ -573,6 +645,7 @@ static irqreturn_t qcom_pcie_ep_global_irq_thread(int irq, void *data)
> } else if (FIELD_GET(PARF_INT_ALL_BME, status)) {
> dev_dbg(dev, "Received BME event. Link is enabled!\n");
> pcie_ep->link_status = QCOM_PCIE_EP_LINK_ENABLED;
> + qcom_pcie_ep_icc_update(pcie_ep);
> pci_epc_bme_notify(pci->ep.epc);
> } else if (FIELD_GET(PARF_INT_ALL_PM_TURNOFF, status)) {
> dev_dbg(dev, "Received PM Turn-off event! Entering L23\n");
> --
> 2.7.4
>

--
மணிவண்ணன் சதாசிவம்

2023-06-27 15:38:39

by Manivannan Sadhasivam

[permalink] [raw]
Subject: Re: [PATCH v5 3/3] PCI: qcom-ep: Add ICC bandwidth voting support

On Tue, Jun 27, 2023 at 12:05:23PM +0530, Pavan Kondeti wrote:
> On Tue, Jun 27, 2023 at 06:31:31AM +0530, Krishna chaitanya chundru wrote:
> > +static void qcom_pcie_ep_icc_update(struct qcom_pcie_ep *pcie_ep)
> > +{
> > + struct dw_pcie *pci = &pcie_ep->pci;
> > + u32 offset, status, bw;
> > + int speed, width;
> > + int ret;
> > +
> > + if (!pcie_ep->icc_mem)
> > + return;
> > +
>
> Is this check needed? interconnect is added as required property and
> probe is failed if interconnect get fails. qcom_pcie_enable_resources()
> which gets called before enabling this interrupt is assuming that
> interconnect available.
>

Even though the current binding requires interconnect, driver needs to be
backwards compatible with old dts where there was no interconnect.

Also, devm_of_icc_get() will return NULL if the property is missing in dts. But
we are just checking for IS_ERR not IS_ERR_OR_NULL. So this check is required.

- Mani

>
> > + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
> > + status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA);
> > +
> > + speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status);
> > + width = FIELD_GET(PCI_EXP_LNKSTA_NLW, status);
> > +
> > + switch (speed) {
> > + case 1:
> > + bw = MBps_to_icc(PCIE_GEN1_BW_MBPS);
> > + break;
> > + case 2:
> > + bw = MBps_to_icc(PCIE_GEN2_BW_MBPS);
> > + break;
> > + case 3:
> > + bw = MBps_to_icc(PCIE_GEN3_BW_MBPS);
> > + break;
> > + default:
> > + dev_warn(pci->dev, "using default GEN4 bandwidth\n");
> > + fallthrough;
> > + case 4:
> > + bw = MBps_to_icc(PCIE_GEN4_BW_MBPS);
> > + break;
> > + }
> > +
> > + ret = icc_set_bw(pcie_ep->icc_mem, 0, width * bw);
> > + if (ret) {
> > + dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
> > + ret);
> > + }
>
> Are you not seeing the below warning from checkpatch?
>
> WARNING: braces {} are not necessary for single statement blocks
>
> > +}
> > +
> > static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep)
> > {
> > int ret;
> > + struct dw_pcie *pci = &pcie_ep->pci;
> >
> > ret = clk_bulk_prepare_enable(pcie_ep->num_clks, pcie_ep->clks);
> > if (ret)
> > @@ -277,6 +331,20 @@ static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep)
> > if (ret)
> > goto err_phy_exit;
> >
> > + /*
> > + * Some Qualcomm platforms require interconnect bandwidth constraints
> > + * to be set before enabling interconnect clocks.
> > + *
> > + * Set an initial peak bandwidth corresponding to single-lane Gen 1
> > + * for the pcie-mem path.
> > + */
> > + ret = icc_set_bw(pcie_ep->icc_mem, 0, MBps_to_icc(PCIE_GEN1_BW_MBPS));
> > + if (ret) {
> > + dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
> > + ret);
> > + goto err_phy_exit;
> > + }
> > +
> > return 0;
>
> Thanks,
> Pavan

--
மணிவண்ணன் சதாசிவம்

Subject: Re: [PATCH v5 3/3] PCI: qcom-ep: Add ICC bandwidth voting support


On 6/27/2023 8:31 PM, Manivannan Sadhasivam wrote:
> On Tue, Jun 27, 2023 at 06:31:31AM +0530, Krishna chaitanya chundru wrote:
>> Add support to vote for ICC bandwidth based on the link
>> speed and width.
>>
>> This patch is inspired from pcie-qcom driver to add basic
>> interconnect support.
>>
>> Reference: commit c4860af88d0c ("PCI: qcom: Add basic interconnect
>> support").
>> Signed-off-by: Krishna chaitanya chundru <[email protected]>
>> ---
>> drivers/pci/controller/dwc/pcie-qcom-ep.c | 73 +++++++++++++++++++++++++++++++
>> 1 file changed, 73 insertions(+)
>>
>> diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
>> index 1435f51..b613817 100644
>> --- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
>> +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
>> @@ -13,6 +13,7 @@
>> #include <linux/debugfs.h>
>> #include <linux/delay.h>
>> #include <linux/gpio/consumer.h>
>> +#include <linux/interconnect.h>
>> #include <linux/mfd/syscon.h>
>> #include <linux/phy/pcie.h>
>> #include <linux/phy/phy.h>
>> @@ -28,6 +29,7 @@
>> #define PARF_SYS_CTRL 0x00
>> #define PARF_DB_CTRL 0x10
>> #define PARF_PM_CTRL 0x20
>> +#define PARF_PM_STTS 0x24
>> #define PARF_MHI_CLOCK_RESET_CTRL 0x174
>> #define PARF_MHI_BASE_ADDR_LOWER 0x178
>> #define PARF_MHI_BASE_ADDR_UPPER 0x17c
>> @@ -128,11 +130,19 @@
>> /* DBI register fields */
>> #define DBI_CON_STATUS_POWER_STATE_MASK GENMASK(1, 0)
>>
>> +#define DBI_LINKCTRLSTATUS 0x80
>> +#define DBI_LINKCTRLSTATUS_SHIFT 16
> not used?
not using these macros so I removed them in next patch.
>> +
>> #define XMLH_LINK_UP 0x400
>> #define CORE_RESET_TIME_US_MIN 1000
>> #define CORE_RESET_TIME_US_MAX 1005
>> #define WAKE_DELAY_US 2000 /* 2 ms */
>>
>> +#define PCIE_GEN1_BW_MBPS 250
>> +#define PCIE_GEN2_BW_MBPS 500
>> +#define PCIE_GEN3_BW_MBPS 985
>> +#define PCIE_GEN4_BW_MBPS 1969
>> +
>> #define to_pcie_ep(x) dev_get_drvdata((x)->dev)
>>
>> enum qcom_pcie_ep_link_status {
>> @@ -178,6 +188,8 @@ struct qcom_pcie_ep {
>> struct phy *phy;
>> struct dentry *debugfs;
>>
>> + struct icc_path *icc_mem;
>> +
>> struct clk_bulk_data *clks;
>> int num_clks;
>>
>> @@ -253,9 +265,51 @@ static void qcom_pcie_dw_stop_link(struct dw_pcie *pci)
>> disable_irq(pcie_ep->perst_irq);
>> }
>>
>> +static void qcom_pcie_ep_icc_update(struct qcom_pcie_ep *pcie_ep)
>> +{
>> + struct dw_pcie *pci = &pcie_ep->pci;
>> + u32 offset, status, bw;
>> + int speed, width;
>> + int ret;
>> +
>> + if (!pcie_ep->icc_mem)
>> + return;
>> +
>> + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
>> + status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA);
>> +
>> + speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status);
>> + width = FIELD_GET(PCI_EXP_LNKSTA_NLW, status);
>> +
>> + switch (speed) {
>> + case 1:
>> + bw = MBps_to_icc(PCIE_GEN1_BW_MBPS);
>> + break;
>> + case 2:
>> + bw = MBps_to_icc(PCIE_GEN2_BW_MBPS);
>> + break;
>> + case 3:
>> + bw = MBps_to_icc(PCIE_GEN3_BW_MBPS);
>> + break;
>> + default:
>> + dev_warn(pci->dev, "using default GEN4 bandwidth\n");
>> + fallthrough;
>> + case 4:
>> + bw = MBps_to_icc(PCIE_GEN4_BW_MBPS);
>> + break;
>> + }
>> +
>> + ret = icc_set_bw(pcie_ep->icc_mem, 0, width * bw);
>> + if (ret) {
>> + dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
>> + ret);
> No need of braces for single line.
done.
>> + }
>> +}
>> +
>> static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep)
>> {
>> int ret;
>> + struct dw_pcie *pci = &pcie_ep->pci;
>>
>> ret = clk_bulk_prepare_enable(pcie_ep->num_clks, pcie_ep->clks);
>> if (ret)
>> @@ -277,6 +331,20 @@ static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep)
>> if (ret)
>> goto err_phy_exit;
>>
>> + /*
>> + * Some Qualcomm platforms require interconnect bandwidth constraints
>> + * to be set before enabling interconnect clocks.
>> + *
>> + * Set an initial peak bandwidth corresponding to single-lane Gen 1
>> + * for the pcie-mem path.
>> + */
>> + ret = icc_set_bw(pcie_ep->icc_mem, 0, MBps_to_icc(PCIE_GEN1_BW_MBPS));
>> + if (ret) {
>> + dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
>> + ret);
>> + goto err_phy_exit;
> Again, you should power off the PHY in the case of error. err_phy_exit is not
> doing that for you.
>
> - Mani

added the code remove the phy power.

-KC

>> + }
>> +
>> return 0;
>>
>> err_phy_exit:
>> @@ -550,6 +618,10 @@ static int qcom_pcie_ep_get_resources(struct platform_device *pdev,
>> if (IS_ERR(pcie_ep->phy))
>> ret = PTR_ERR(pcie_ep->phy);
>>
>> + pcie_ep->icc_mem = devm_of_icc_get(dev, "pcie-mem");
>> + if (IS_ERR(pcie_ep->icc_mem))
>> + ret = PTR_ERR(pcie_ep->icc_mem);
>> +
>> return ret;
>> }
>>
>> @@ -573,6 +645,7 @@ static irqreturn_t qcom_pcie_ep_global_irq_thread(int irq, void *data)
>> } else if (FIELD_GET(PARF_INT_ALL_BME, status)) {
>> dev_dbg(dev, "Received BME event. Link is enabled!\n");
>> pcie_ep->link_status = QCOM_PCIE_EP_LINK_ENABLED;
>> + qcom_pcie_ep_icc_update(pcie_ep);
>> pci_epc_bme_notify(pci->ep.epc);
>> } else if (FIELD_GET(PARF_INT_ALL_PM_TURNOFF, status)) {
>> dev_dbg(dev, "Received PM Turn-off event! Entering L23\n");
>> --
>> 2.7.4
>>

Subject: Re: [PATCH v5 3/3] PCI: qcom-ep: Add ICC bandwidth voting support


On 6/27/2023 12:05 PM, Pavan Kondeti wrote:
> On Tue, Jun 27, 2023 at 06:31:31AM +0530, Krishna chaitanya chundru wrote:
>> +static void qcom_pcie_ep_icc_update(struct qcom_pcie_ep *pcie_ep)
>> +{
>> + struct dw_pcie *pci = &pcie_ep->pci;
>> + u32 offset, status, bw;
>> + int speed, width;
>> + int ret;
>> +
>> + if (!pcie_ep->icc_mem)
>> + return;
>> +
> Is this check needed? interconnect is added as required property and
> probe is failed if interconnect get fails. qcom_pcie_enable_resources()
> which gets called before enabling this interrupt is assuming that
> interconnect available.
>
>
>> + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
>> + status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA);
>> +
>> + speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status);
>> + width = FIELD_GET(PCI_EXP_LNKSTA_NLW, status);
>> +
>> + switch (speed) {
>> + case 1:
>> + bw = MBps_to_icc(PCIE_GEN1_BW_MBPS);
>> + break;
>> + case 2:
>> + bw = MBps_to_icc(PCIE_GEN2_BW_MBPS);
>> + break;
>> + case 3:
>> + bw = MBps_to_icc(PCIE_GEN3_BW_MBPS);
>> + break;
>> + default:
>> + dev_warn(pci->dev, "using default GEN4 bandwidth\n");
>> + fallthrough;
>> + case 4:
>> + bw = MBps_to_icc(PCIE_GEN4_BW_MBPS);
>> + break;
>> + }
>> +
>> + ret = icc_set_bw(pcie_ep->icc_mem, 0, width * bw);
>> + if (ret) {
>> + dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
>> + ret);
>> + }
> Are you not seeing the below warning from checkpatch?
>
> WARNING: braces {} are not necessary for single statement blocks

checkpatch is not giving warnings for this.

I removed the braces.

-KC

>> +}
>> +
>> static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep)
>> {
>> int ret;
>> + struct dw_pcie *pci = &pcie_ep->pci;
>>
>> ret = clk_bulk_prepare_enable(pcie_ep->num_clks, pcie_ep->clks);
>> if (ret)
>> @@ -277,6 +331,20 @@ static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep)
>> if (ret)
>> goto err_phy_exit;
>>
>> + /*
>> + * Some Qualcomm platforms require interconnect bandwidth constraints
>> + * to be set before enabling interconnect clocks.
>> + *
>> + * Set an initial peak bandwidth corresponding to single-lane Gen 1
>> + * for the pcie-mem path.
>> + */
>> + ret = icc_set_bw(pcie_ep->icc_mem, 0, MBps_to_icc(PCIE_GEN1_BW_MBPS));
>> + if (ret) {
>> + dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
>> + ret);
>> + goto err_phy_exit;
>> + }
>> +
>> return 0;
> Thanks,
> Pavan