[PATCH V3 00/21] Enhancements to pcie-tegra194 driver

[PATCH V3 00/21] Enhancements to pcie-tegra194 driver

[Vidya Sagar]

This patch series contains enhancements to the pcie-tegra194.c driver
that works for both Tegra194 and Tegra234 SoCs and for both RootPort
and Endpoint modes.

This patch series depends on the following series in the same order

PCI: designware-ep: Fix DBI access before core init
https://patchwork.ozlabs.org/project/linux-pci/list/?series=322681

PCI: endpoint: Rework the EPC to EPF notification
https://patchwork.kernel.org/project/linux-pci/list/?series=683493

Add DeInit support in the PCIe Endpoint framework
https://patchwork.kernel.org/project/linux-pci/list/?series=685157

V3:
* Addressed review comments from Bjorn
* Added new patches to the series

V2:
* Addressed review comments from test bot and Vinod

Vidya Sagar (21):
  PCI: tegra194: Use devm_gpiod_get_optional() to parse
    "nvidia,refclk-select"
  PCI: tegra194: Drive CLKREQ signal low explicitly
  PCI: tegra194: Fix polling delay for L2 state
  PCI: tegra194: Handle errors in BPMP response
  PCI: tegra194: Apply pinctrl settings for both PCIe RP and EP
  PCI: tegra194: Refactor LTSSM state polling on surprise down
  PCI: tegra194: Disable direct speed change for EP
  phy: tegra: p2u: Set ENABLE_L2_EXIT_RATE_CHANGE in calibration
  PCI: tegra194: Calibrate P2U for endpoint mode
  PCI: tegra194: Free resources during controller deinitialization
  PCI: tegra194: Remove IRQF_ONESHOT flag during Endpoint interrupt
    registration
  PCI: tegra194: Enable DMA interrupt
  PCI: tegra194: Enable hardware hot reset mode in Endpoint
  PCI: tegra194: Allow system suspend when the Endpoint link is not up
  PCI: tegra194: Disable L1.2 capability of Tegra234 EP
  PCI: tegra194: Set LTR message request before PCIe link up
  PCI: tegra194: Reduce AXI slave timeout value
  PCI: tegra194: Don't force the device into the D0 state before L2
  PCI: tegra194: Free up EP resources during remove()
  dt-bindings: PCI: tegra194: Add monitor clock support
  PCI: tegra194: Add core monitor clock support

 .../bindings/pci/nvidia,tegra194-pcie-ep.yaml |   6 +-
 .../bindings/pci/nvidia,tegra194-pcie.yaml    |   6 +-
 drivers/pci/controller/dwc/pcie-tegra194.c    | 261 ++++++++++++------
 drivers/phy/tegra/phy-tegra194-p2u.c          |  14 +
 4 files changed, 194 insertions(+), 93 deletions(-)

-- 
2.17.1

[PATCH V3 01/21] PCI: tegra194: Use devm_gpiod_get_optional() to parse "nvidia,refclk-select"

[Vidya Sagar]

The GPIO DT property "nvidia,refclk-select" to select the PCIe reference
clock is optional. Use devm_gpiod_get_optional() to get it.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* None

V2:
* None

 drivers/pci/controller/dwc/pcie-tegra194.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 9e64b948f999..d7ab33931de4 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1233,9 +1233,9 @@ static int tegra_pcie_dw_parse_dt(struct tegra_pcie_dw *pcie)
 		return err;
 	}
 
-	pcie->pex_refclk_sel_gpiod = devm_gpiod_get(pcie->dev,
-						    "nvidia,refclk-select",
-						    GPIOD_OUT_HIGH);
+	pcie->pex_refclk_sel_gpiod = devm_gpiod_get_optional(pcie->dev,
+							     "nvidia,refclk-select",
+							     GPIOD_OUT_HIGH);
 	if (IS_ERR(pcie->pex_refclk_sel_gpiod)) {
 		int err = PTR_ERR(pcie->pex_refclk_sel_gpiod);
 		const char *level = KERN_ERR;
-- 
2.17.1

[PATCH V3 02/21] PCI: tegra194: Drive CLKREQ signal low explicitly

[Vidya Sagar]

Currently, the default setting is that CLKREQ signal of a Root Port
is internally overridden to '0' to enable REFCLK to flow out to the slot.
It is observed that one of the PCIe switches (case in point Broadcom PCIe
Gen4 switch) is propagating the CLKREQ signal of the root port to the
downstream side of the switch and expecting the endpoints to pull it low
so that it (PCIe switch) can give out the REFCLK although the Switch as
such doesn't support CLK-PM or ASPM-L1SS. So, as a workaround, this patch
drives the CLKREQ of the Root Port itself low to avoid link up issues
between PCIe switch downstream port and endpoints. This is not a wrong
thing to do after all the CLKREQ is anyway being overridden to '0'
internally and now it is just that the same is being propagated outside
also.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* Reworded the commit message

V2:
* None

 drivers/pci/controller/dwc/pcie-tegra194.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index d7ab33931de4..a33c86e3de9d 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -47,6 +47,7 @@
 #define APPL_PINMUX_CLKREQ_OVERRIDE		BIT(3)
 #define APPL_PINMUX_CLK_OUTPUT_IN_OVERRIDE_EN	BIT(4)
 #define APPL_PINMUX_CLK_OUTPUT_IN_OVERRIDE	BIT(5)
+#define APPL_PINMUX_CLKREQ_DEFAULT_VALUE	BIT(13)
 
 #define APPL_CTRL				0x4
 #define APPL_CTRL_SYS_PRE_DET_STATE		BIT(6)
@@ -1510,6 +1511,7 @@ static int tegra_pcie_config_controller(struct tegra_pcie_dw *pcie,
 		val = appl_readl(pcie, APPL_PINMUX);
 		val |= APPL_PINMUX_CLKREQ_OVERRIDE_EN;
 		val &= ~APPL_PINMUX_CLKREQ_OVERRIDE;
+		val &= ~APPL_PINMUX_CLKREQ_DEFAULT_VALUE;
 		appl_writel(pcie, val, APPL_PINMUX);
 	}
 
-- 
2.17.1

[PATCH V3 03/21] PCI: tegra194: Fix polling delay for L2 state

[Vidya Sagar]

As per PCIe spec r6.0, sec 5.3.3.2.1, after sending PME_Turn_Off message,
Root port should wait for 1~10 msec for PME_TO_Ack message. Currently,
driver is polling for 10 msec with 1 usec delay which is aggressive.
Change it to 10 msec polling with 100 usec delay. Since this function
is used in non-atomic context only, use non-atomic poll function.

Fixes: 56e15a238d92 ("PCI: tegra: Add Tegra194 PCIe support")
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* Changed atomic call to non-atomic call
* Reworded the commit message

V2:
* None

 drivers/pci/controller/dwc/pcie-tegra194.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index a33c86e3de9d..685aee378c93 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -207,7 +207,8 @@
 #define CAP_SPCIE_CAP_OFF_USP_TX_PRESET0_MASK	GENMASK(11, 8)
 #define CAP_SPCIE_CAP_OFF_USP_TX_PRESET0_SHIFT	8
 
-#define PME_ACK_TIMEOUT 10000
+#define PME_ACK_DELAY		100   /* 100 us */
+#define PME_ACK_TIMEOUT		10000 /* 10 ms */
 
 #define LTSSM_TIMEOUT 50000	/* 50ms */
 
@@ -1611,9 +1612,9 @@ static int tegra_pcie_try_link_l2(struct tegra_pcie_dw *pcie)
 	val |= APPL_PM_XMT_TURNOFF_STATE;
 	appl_writel(pcie, val, APPL_RADM_STATUS);
 
-	return readl_poll_timeout_atomic(pcie->appl_base + APPL_DEBUG, val,
-				 val & APPL_DEBUG_PM_LINKST_IN_L2_LAT,
-				 1, PME_ACK_TIMEOUT);
+	return readl_poll_timeout(pcie->appl_base + APPL_DEBUG, val,
+				  val & APPL_DEBUG_PM_LINKST_IN_L2_LAT,
+				  PME_ACK_DELAY, PME_ACK_TIMEOUT);
 }
 
 static void tegra_pcie_dw_pme_turnoff(struct tegra_pcie_dw *pcie)
-- 
2.17.1

[PATCH V3 04/21] PCI: tegra194: Handle errors in BPMP response

[Vidya Sagar]

The return value from tegra_bpmp_transfer indicates the success or
failure of the IPC transaction with BPMP. If the transaction
succeeded, we also need to check the actual command's result code.
Add code to do this.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* None

V2:
* None

 drivers/pci/controller/dwc/pcie-tegra194.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 685aee378c93..ae7e0d8f693b 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1260,6 +1260,7 @@ static int tegra_pcie_bpmp_set_ctrl_state(struct tegra_pcie_dw *pcie,
 	struct mrq_uphy_response resp;
 	struct tegra_bpmp_message msg;
 	struct mrq_uphy_request req;
+	int err;
 
 	/*
 	 * Controller-5 doesn't need to have its state set by BPMP-FW in
@@ -1282,7 +1283,13 @@ static int tegra_pcie_bpmp_set_ctrl_state(struct tegra_pcie_dw *pcie,
 	msg.rx.data = &resp;
 	msg.rx.size = sizeof(resp);
 
-	return tegra_bpmp_transfer(pcie->bpmp, &msg);
+	err = tegra_bpmp_transfer(pcie->bpmp, &msg);
+	if (err)
+		return err;
+	if (msg.rx.ret)
+		return -EINVAL;
+
+	return 0;
 }
 
 static int tegra_pcie_bpmp_set_pll_state(struct tegra_pcie_dw *pcie,
@@ -1291,6 +1298,7 @@ static int tegra_pcie_bpmp_set_pll_state(struct tegra_pcie_dw *pcie,
 	struct mrq_uphy_response resp;
 	struct tegra_bpmp_message msg;
 	struct mrq_uphy_request req;
+	int err;
 
 	memset(&req, 0, sizeof(req));
 	memset(&resp, 0, sizeof(resp));
@@ -1310,7 +1318,13 @@ static int tegra_pcie_bpmp_set_pll_state(struct tegra_pcie_dw *pcie,
 	msg.rx.data = &resp;
 	msg.rx.size = sizeof(resp);
 
-	return tegra_bpmp_transfer(pcie->bpmp, &msg);
+	err = tegra_bpmp_transfer(pcie->bpmp, &msg);
+	if (err)
+		return err;
+	if (msg.rx.ret)
+		return -EINVAL;
+
+	return 0;
 }
 
 static void tegra_pcie_downstream_dev_to_D0(struct tegra_pcie_dw *pcie)
-- 
2.17.1

Re: [PATCH V3 04/21] PCI: tegra194: Handle errors in BPMP response

[Lorenzo Pieralisi]

On Fri, Oct 14, 2022 at 12:08:37AM +0530, Vidya Sagar wrote:
> The return value from tegra_bpmp_transfer indicates the success or
> failure of the IPC transaction with BPMP. If the transaction
> succeeded, we also need to check the actual command's result code.
> Add code to do this.
> 
> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
> ---
> V3:
> * None
> 
> V2:
> * None
> 
>  drivers/pci/controller/dwc/pcie-tegra194.c | 18 ++++++++++++++++--
>  1 file changed, 16 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
> index 685aee378c93..ae7e0d8f693b 100644
> --- a/drivers/pci/controller/dwc/pcie-tegra194.c
> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
> @@ -1260,6 +1260,7 @@ static int tegra_pcie_bpmp_set_ctrl_state(struct tegra_pcie_dw *pcie,
>  	struct mrq_uphy_response resp;
>  	struct tegra_bpmp_message msg;
>  	struct mrq_uphy_request req;
> +	int err;
>  
>  	/*
>  	 * Controller-5 doesn't need to have its state set by BPMP-FW in
> @@ -1282,7 +1283,13 @@ static int tegra_pcie_bpmp_set_ctrl_state(struct tegra_pcie_dw *pcie,
>  	msg.rx.data = &resp;
>  	msg.rx.size = sizeof(resp);
>  
> -	return tegra_bpmp_transfer(pcie->bpmp, &msg);
> +	err = tegra_bpmp_transfer(pcie->bpmp, &msg);
> +	if (err)
> +		return err;
> +	if (msg.rx.ret)
> +		return -EINVAL;
> +
> +	return 0;
>  }
>  
>  static int tegra_pcie_bpmp_set_pll_state(struct tegra_pcie_dw *pcie,
> @@ -1291,6 +1298,7 @@ static int tegra_pcie_bpmp_set_pll_state(struct tegra_pcie_dw *pcie,
>  	struct mrq_uphy_response resp;
>  	struct tegra_bpmp_message msg;
>  	struct mrq_uphy_request req;
> +	int err;
>  
>  	memset(&req, 0, sizeof(req));
>  	memset(&resp, 0, sizeof(resp));
> @@ -1310,7 +1318,13 @@ static int tegra_pcie_bpmp_set_pll_state(struct tegra_pcie_dw *pcie,
>  	msg.rx.data = &resp;
>  	msg.rx.size = sizeof(resp);
>  
> -	return tegra_bpmp_transfer(pcie->bpmp, &msg);
> +	err = tegra_bpmp_transfer(pcie->bpmp, &msg);
> +	if (err)
> +		return err;
> +	if (msg.rx.ret)
> +		return -EINVAL;

I wonder whether you can embed the return value check within
the function itself.

Lorenzo

> +
> +	return 0;
>  }
>  
>  static void tegra_pcie_downstream_dev_to_D0(struct tegra_pcie_dw *pcie)
> -- 
> 2.17.1
> 
> 
> -- 
> linux-phy mailing list
> linux-phy@lists.infradead.org
> https://lists.infradead.org/mailman/listinfo/linux-phy

[PATCH V3 05/21] PCI: tegra194: Apply pinctrl settings for both PCIe RP and EP

[Vidya Sagar]

PERST# and CLKREQ# pinctrl settings should be applied for both root port
and endpoint mode. Move pinctrl_pm_select_default_state() function call
from root port specific configuration function to probe().

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* None

V2:
* None

 drivers/pci/controller/dwc/pcie-tegra194.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index ae7e0d8f693b..69e11a74a0d7 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1716,12 +1716,6 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie)
 		goto fail_pm_get_sync;
 	}
 
-	ret = pinctrl_pm_select_default_state(dev);
-	if (ret < 0) {
-		dev_err(dev, "Failed to configure sideband pins: %d\n", ret);
-		goto fail_pm_get_sync;
-	}
-
 	ret = tegra_pcie_init_controller(pcie);
 	if (ret < 0) {
 		dev_err(dev, "Failed to initialize controller: %d\n", ret);
@@ -2191,6 +2185,19 @@ static int tegra_pcie_dw_probe(struct platform_device *pdev)
 	pp = &pci->pp;
 	pp->num_vectors = MAX_MSI_IRQS;
 
+	ret = pinctrl_pm_select_default_state(dev);
+	if (ret < 0) {
+		const char *level = KERN_ERR;
+
+		if (ret == -EPROBE_DEFER)
+			level = KERN_DEBUG;
+
+		dev_printk(level, dev,
+			   "Failed to configure sideband pins: %d\n",
+			   ret);
+		return ret;
+	}
+
 	ret = tegra_pcie_dw_parse_dt(pcie);
 	if (ret < 0) {
 		const char *level = KERN_ERR;
-- 
2.17.1

[PATCH V3 06/21] PCI: tegra194: Refactor LTSSM state polling on surprise down

[Vidya Sagar]

On surprise down, LTSSM state transits from L0 -> Recovery.RcvrLock ->
Recovery.RcvrSpeed -> Gen1 Recovery.RcvrLock -> Detect. Recovery.RcvrLock
and Recovery.RcvrSpeed transit times are 24 msec and 48 msec respectively.
So, the total time taken to transit from L0 to detect state is ~96 msec.
Hence, increase the poll time to 120 msec.

Disable the LTSSM state after it transits to detect to avoid LTSSM
toggling between polling and detect states.

tegra_pcie_dw_pme_turnoff() function is called in non-atomic context
only, so use the non-atomic poll function.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* Addressed review comments from Bjorn
* Reworded the commit message

V2:
* None

 drivers/pci/controller/dwc/pcie-tegra194.c | 55 +++++++++++++---------
 1 file changed, 32 insertions(+), 23 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 69e11a74a0d7..897e2a22bcd3 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -141,7 +141,11 @@
 #define APPL_DEBUG_PM_LINKST_IN_L0		0x11
 #define APPL_DEBUG_LTSSM_STATE_MASK		GENMASK(8, 3)
 #define APPL_DEBUG_LTSSM_STATE_SHIFT		3
-#define LTSSM_STATE_PRE_DETECT			5
+#define LTSSM_STATE_DETECT_QUIET		0x00
+#define LTSSM_STATE_DETECT_ACT			0x08
+#define LTSSM_STATE_PRE_DETECT_QUIET		0x28
+#define LTSSM_STATE_DETECT_WAIT			0x30
+#define LTSSM_STATE_L2_IDLE			0xa8
 
 #define APPL_RADM_STATUS			0xE4
 #define APPL_PM_XMT_TURNOFF_STATE		BIT(0)
@@ -210,7 +214,8 @@
 #define PME_ACK_DELAY		100   /* 100 us */
 #define PME_ACK_TIMEOUT		10000 /* 10 ms */
 
-#define LTSSM_TIMEOUT 50000	/* 50ms */
+#define LTSSM_DELAY		10000	/* 10 ms */
+#define LTSSM_TIMEOUT		120000	/* 120 ms */
 
 #define GEN3_GEN4_EQ_PRESET_INIT	5
 
@@ -1663,23 +1668,22 @@ static void tegra_pcie_dw_pme_turnoff(struct tegra_pcie_dw *pcie)
 		data &= ~APPL_PINMUX_PEX_RST;
 		appl_writel(pcie, data, APPL_PINMUX);
 
+		err = readl_poll_timeout(pcie->appl_base + APPL_DEBUG, data,
+			((data & APPL_DEBUG_LTSSM_STATE_MASK) == LTSSM_STATE_DETECT_QUIET) ||
+			((data & APPL_DEBUG_LTSSM_STATE_MASK) == LTSSM_STATE_DETECT_ACT) ||
+			((data & APPL_DEBUG_LTSSM_STATE_MASK) == LTSSM_STATE_PRE_DETECT_QUIET) ||
+			((data & APPL_DEBUG_LTSSM_STATE_MASK) == LTSSM_STATE_DETECT_WAIT),
+			LTSSM_DELAY, LTSSM_TIMEOUT);
+		if (err)
+			dev_info(pcie->dev, "Link didn't go to detect state\n");
+
 		/*
-		 * Some cards do not go to detect state even after de-asserting
-		 * PERST#. So, de-assert LTSSM to bring link to detect state.
+		 * Deassert LTSSM state to stop the state toggling between
+		 * polling and detect.
 		 */
 		data = readl(pcie->appl_base + APPL_CTRL);
 		data &= ~APPL_CTRL_LTSSM_EN;
 		writel(data, pcie->appl_base + APPL_CTRL);
-
-		err = readl_poll_timeout_atomic(pcie->appl_base + APPL_DEBUG,
-						data,
-						((data &
-						APPL_DEBUG_LTSSM_STATE_MASK) >>
-						APPL_DEBUG_LTSSM_STATE_SHIFT) ==
-						LTSSM_STATE_PRE_DETECT,
-						1, LTSSM_TIMEOUT);
-		if (err)
-			dev_info(pcie->dev, "Link didn't go to detect state\n");
 	}
 	/*
 	 * DBI registers may not be accessible after this as PLL-E would be
@@ -1769,19 +1773,24 @@ static void pex_ep_event_pex_rst_assert(struct tegra_pcie_dw *pcie)
 	if (pcie->ep_state == EP_STATE_DISABLED)
 		return;
 
-	/* Disable LTSSM */
+	ret = readl_poll_timeout(pcie->appl_base + APPL_DEBUG, val,
+		((val & APPL_DEBUG_LTSSM_STATE_MASK) == LTSSM_STATE_DETECT_QUIET) ||
+		((val & APPL_DEBUG_LTSSM_STATE_MASK) == LTSSM_STATE_DETECT_ACT) ||
+		((val & APPL_DEBUG_LTSSM_STATE_MASK) == LTSSM_STATE_PRE_DETECT_QUIET) ||
+		((val & APPL_DEBUG_LTSSM_STATE_MASK) == LTSSM_STATE_DETECT_WAIT) ||
+		((val & APPL_DEBUG_LTSSM_STATE_MASK) == LTSSM_STATE_L2_IDLE),
+		LTSSM_DELAY, LTSSM_TIMEOUT);
+	if (ret)
+		dev_err(pcie->dev, "LTSSM state: 0x%x timeout: %d\n", val, ret);
+
+	/*
+	 * Deassert LTSSM state to stop the state toggling between
+	 * polling and detect.
+	 */
 	val = appl_readl(pcie, APPL_CTRL);
 	val &= ~APPL_CTRL_LTSSM_EN;
 	appl_writel(pcie, val, APPL_CTRL);
 
-	ret = readl_poll_timeout(pcie->appl_base + APPL_DEBUG, val,
-				 ((val & APPL_DEBUG_LTSSM_STATE_MASK) >>
-				 APPL_DEBUG_LTSSM_STATE_SHIFT) ==
-				 LTSSM_STATE_PRE_DETECT,
-				 1, LTSSM_TIMEOUT);
-	if (ret)
-		dev_err(pcie->dev, "Failed to go Detect state: %d\n", ret);
-
 	reset_control_assert(pcie->core_rst);
 
 	tegra_pcie_disable_phy(pcie);
-- 
2.17.1

[PATCH V3 07/21] PCI: tegra194: Disable direct speed change for EP

[Vidya Sagar]

Disable direct speed change for the endpoint to prevent it from initiating
the speed change post physical layer link up at gen1. This leaves the speed
change ownership with the host.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* Reworded the commit message

V2:
* None

 drivers/pci/controller/dwc/pcie-tegra194.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 897e2a22bcd3..dff38f73d9a7 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1929,6 +1929,10 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
 
 	reset_control_deassert(pcie->core_rst);
 
+	val = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
+	val &= ~PORT_LOGIC_SPEED_CHANGE;
+	dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, val);
+
 	if (pcie->update_fc_fixup) {
 		val = dw_pcie_readl_dbi(pci, CFG_TIMER_CTRL_MAX_FUNC_NUM_OFF);
 		val |= 0x1 << CFG_TIMER_CTRL_ACK_NAK_SHIFT;
-- 
2.17.1

[PATCH V3 08/21] phy: tegra: p2u: Set ENABLE_L2_EXIT_RATE_CHANGE in calibration

[Vidya Sagar]

Set ENABLE_L2_EXIT_RATE_CHANGE register bit to request UPHY PLL rate change
to Gen1 during initialization. This helps in the below surprise link down
cases,
  - Surprise link down happens at Gen3/Gen4 link speed.
  - Surprise link down happens and external REFCLK is cut off, which causes
UPHY PLL rate to deviate to an invalid rate.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* Removed "Reported-by: kernel test robot <lkp@intel.com>" based on Bjorn's review comment
* Reworded the commit message

V2:
* Addressed review comment from test bot and Vinod

 drivers/phy/tegra/phy-tegra194-p2u.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/phy/tegra/phy-tegra194-p2u.c b/drivers/phy/tegra/phy-tegra194-p2u.c
index 1415ca71de38..633e6b747275 100644
--- a/drivers/phy/tegra/phy-tegra194-p2u.c
+++ b/drivers/phy/tegra/phy-tegra194-p2u.c
@@ -15,6 +15,7 @@
 #include <linux/phy/phy.h>
 
 #define P2U_CONTROL_CMN			0x74
+#define P2U_CONTROL_CMN_ENABLE_L2_EXIT_RATE_CHANGE		BIT(13)
 #define P2U_CONTROL_CMN_SKP_SIZE_PROTECTION_EN			BIT(20)
 
 #define P2U_PERIODIC_EQ_CTRL_GEN3	0xc0
@@ -85,8 +86,21 @@ static int tegra_p2u_power_on(struct phy *x)
 	return 0;
 }
 
+static int tegra_p2u_calibrate(struct phy *x)
+{
+	struct tegra_p2u *phy = phy_get_drvdata(x);
+	u32 val;
+
+	val = p2u_readl(phy, P2U_CONTROL_CMN);
+	val |= P2U_CONTROL_CMN_ENABLE_L2_EXIT_RATE_CHANGE;
+	p2u_writel(phy, val, P2U_CONTROL_CMN);
+
+	return 0;
+}
+
 static const struct phy_ops ops = {
 	.power_on = tegra_p2u_power_on,
+	.calibrate = tegra_p2u_calibrate,
 	.owner = THIS_MODULE,
 };
 
-- 
2.17.1

Re: [PATCH V3 08/21] phy: tegra: p2u: Set ENABLE_L2_EXIT_RATE_CHANGE in calibration

[Vinod Koul]

On 14-10-22, 00:08, Vidya Sagar wrote:
> Set ENABLE_L2_EXIT_RATE_CHANGE register bit to request UPHY PLL rate change
> to Gen1 during initialization. This helps in the below surprise link down
> cases,
>   - Surprise link down happens at Gen3/Gen4 link speed.
>   - Surprise link down happens and external REFCLK is cut off, which causes
> UPHY PLL rate to deviate to an invalid rate.

This looks okay to me and I can go ahead and apply, PCI patches can come
thru PCI tree and whenever ready use .calibrate() ?

> 
> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
> ---
> V3:
> * Removed "Reported-by: kernel test robot <lkp@intel.com>" based on Bjorn's review comment
> * Reworded the commit message
> 
> V2:
> * Addressed review comment from test bot and Vinod
> 
>  drivers/phy/tegra/phy-tegra194-p2u.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/drivers/phy/tegra/phy-tegra194-p2u.c b/drivers/phy/tegra/phy-tegra194-p2u.c
> index 1415ca71de38..633e6b747275 100644
> --- a/drivers/phy/tegra/phy-tegra194-p2u.c
> +++ b/drivers/phy/tegra/phy-tegra194-p2u.c
> @@ -15,6 +15,7 @@
>  #include <linux/phy/phy.h>
>  
>  #define P2U_CONTROL_CMN			0x74
> +#define P2U_CONTROL_CMN_ENABLE_L2_EXIT_RATE_CHANGE		BIT(13)
>  #define P2U_CONTROL_CMN_SKP_SIZE_PROTECTION_EN			BIT(20)
>  
>  #define P2U_PERIODIC_EQ_CTRL_GEN3	0xc0
> @@ -85,8 +86,21 @@ static int tegra_p2u_power_on(struct phy *x)
>  	return 0;
>  }
>  
> +static int tegra_p2u_calibrate(struct phy *x)
> +{
> +	struct tegra_p2u *phy = phy_get_drvdata(x);
> +	u32 val;
> +
> +	val = p2u_readl(phy, P2U_CONTROL_CMN);
> +	val |= P2U_CONTROL_CMN_ENABLE_L2_EXIT_RATE_CHANGE;
> +	p2u_writel(phy, val, P2U_CONTROL_CMN);
> +
> +	return 0;
> +}
> +
>  static const struct phy_ops ops = {
>  	.power_on = tegra_p2u_power_on,
> +	.calibrate = tegra_p2u_calibrate,
>  	.owner = THIS_MODULE,
>  };
>  
> -- 
> 2.17.1

-- 
~Vinod

Re: [PATCH V3 08/21] phy: tegra: p2u: Set ENABLE_L2_EXIT_RATE_CHANGE in calibration

[Vidya Sagar]

Thanks for the review and yes please go ahead and apply.

Thanks,
Vidya Sagar

On 10/28/2022 5:12 PM, Vinod Koul wrote:
> External email: Use caution opening links or attachments
> 
> 
> On 14-10-22, 00:08, Vidya Sagar wrote:
>> Set ENABLE_L2_EXIT_RATE_CHANGE register bit to request UPHY PLL rate change
>> to Gen1 during initialization. This helps in the below surprise link down
>> cases,
>>    - Surprise link down happens at Gen3/Gen4 link speed.
>>    - Surprise link down happens and external REFCLK is cut off, which causes
>> UPHY PLL rate to deviate to an invalid rate.
> 
> This looks okay to me and I can go ahead and apply, PCI patches can come
> thru PCI tree and whenever ready use .calibrate() ?
> 
>>
>> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
>> ---
>> V3:
>> * Removed "Reported-by: kernel test robot <lkp@intel.com>" based on Bjorn's review comment
>> * Reworded the commit message
>>
>> V2:
>> * Addressed review comment from test bot and Vinod
>>
>>   drivers/phy/tegra/phy-tegra194-p2u.c | 14 ++++++++++++++
>>   1 file changed, 14 insertions(+)
>>
>> diff --git a/drivers/phy/tegra/phy-tegra194-p2u.c b/drivers/phy/tegra/phy-tegra194-p2u.c
>> index 1415ca71de38..633e6b747275 100644
>> --- a/drivers/phy/tegra/phy-tegra194-p2u.c
>> +++ b/drivers/phy/tegra/phy-tegra194-p2u.c
>> @@ -15,6 +15,7 @@
>>   #include <linux/phy/phy.h>
>>
>>   #define P2U_CONTROL_CMN                      0x74
>> +#define P2U_CONTROL_CMN_ENABLE_L2_EXIT_RATE_CHANGE           BIT(13)
>>   #define P2U_CONTROL_CMN_SKP_SIZE_PROTECTION_EN                       BIT(20)
>>
>>   #define P2U_PERIODIC_EQ_CTRL_GEN3    0xc0
>> @@ -85,8 +86,21 @@ static int tegra_p2u_power_on(struct phy *x)
>>        return 0;
>>   }
>>
>> +static int tegra_p2u_calibrate(struct phy *x)
>> +{
>> +     struct tegra_p2u *phy = phy_get_drvdata(x);
>> +     u32 val;
>> +
>> +     val = p2u_readl(phy, P2U_CONTROL_CMN);
>> +     val |= P2U_CONTROL_CMN_ENABLE_L2_EXIT_RATE_CHANGE;
>> +     p2u_writel(phy, val, P2U_CONTROL_CMN);
>> +
>> +     return 0;
>> +}
>> +
>>   static const struct phy_ops ops = {
>>        .power_on = tegra_p2u_power_on,
>> +     .calibrate = tegra_p2u_calibrate,
>>        .owner = THIS_MODULE,
>>   };
>>
>> --
>> 2.17.1
> 
> --
> ~Vinod
> 

Re: [PATCH V3 08/21] phy: tegra: p2u: Set ENABLE_L2_EXIT_RATE_CHANGE in calibration

[Vinod Koul]

On 14-10-22, 00:08, Vidya Sagar wrote:
> Set ENABLE_L2_EXIT_RATE_CHANGE register bit to request UPHY PLL rate change
> to Gen1 during initialization. This helps in the below surprise link down
> cases,
>   - Surprise link down happens at Gen3/Gen4 link speed.
>   - Surprise link down happens and external REFCLK is cut off, which causes
> UPHY PLL rate to deviate to an invalid rate.

Applied, thanks

-- 
~Vinod

[PATCH V3 09/21] PCI: tegra194: Calibrate P2U for endpoint mode

[Vidya Sagar]

Calibrate P2U for endpoint controller to request UPHY PLL rate change to
Gen1 during initialization. This helps to reset stale PLL state from the
previous bad link state.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* Reworded the commit message

V2:
* None

 drivers/pci/controller/dwc/pcie-tegra194.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index dff38f73d9a7..910dc6c2154e 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1130,6 +1130,9 @@ static int tegra_pcie_enable_phy(struct tegra_pcie_dw *pcie)
 		ret = phy_power_on(pcie->phys[i]);
 		if (ret < 0)
 			goto phy_exit;
+
+		if (pcie->of_data->mode == DW_PCIE_EP_TYPE)
+			phy_calibrate(pcie->phys[i]);
 	}
 
 	return 0;
-- 
2.17.1

[PATCH V3 10/21] PCI: tegra194: Free resources during controller deinitialization

[Vidya Sagar]

Call dw_pcie_ep_deinit() during controller deinitialization to free the
resources allocated in common DesignWare driver.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* This is a new patch in this series

 drivers/pci/controller/dwc/pcie-tegra194.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 910dc6c2154e..7820bf4b9786 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1770,12 +1770,16 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie)
 
 static void pex_ep_event_pex_rst_assert(struct tegra_pcie_dw *pcie)
 {
+	struct dw_pcie *pci = &pcie->pci;
+	struct dw_pcie_ep *ep = &pci->ep;
 	u32 val;
 	int ret;
 
 	if (pcie->ep_state == EP_STATE_DISABLED)
 		return;
 
+	dw_pcie_ep_deinit_notify(ep);
+
 	ret = readl_poll_timeout(pcie->appl_base + APPL_DEBUG, val,
 		((val & APPL_DEBUG_LTSSM_STATE_MASK) == LTSSM_STATE_DETECT_QUIET) ||
 		((val & APPL_DEBUG_LTSSM_STATE_MASK) == LTSSM_STATE_DETECT_ACT) ||
-- 
2.17.1

[PATCH V3 11/21] PCI: tegra194: Remove IRQF_ONESHOT flag during Endpoint interrupt registration

[Vidya Sagar]

Tegra PCIe endpoint has a common interrupt that notifies hardware events
like link up, LTR send, etc. DMA completion event is also notified over
this interrupt. Remove IRQF_ONESHOT flag from interrupt registration and
allow DMA driver to share this interrupt.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* This is a new patch in this series

 drivers/pci/controller/dwc/pcie-tegra194.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 7820bf4b9786..786e5d5f43b9 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -2354,7 +2354,7 @@ static int tegra_pcie_dw_probe(struct platform_device *pdev)
 		ret = devm_request_threaded_irq(dev, pp->irq,
 						tegra_pcie_ep_hard_irq,
 						tegra_pcie_ep_irq_thread,
-						IRQF_SHARED | IRQF_ONESHOT,
+						IRQF_SHARED,
 						"tegra-pcie-ep-intr", pcie);
 		if (ret) {
 			dev_err(dev, "Failed to request IRQ %d: %d\n", pp->irq,
-- 
2.17.1

Re: [PATCH V3 11/21] PCI: tegra194: Remove IRQF_ONESHOT flag during Endpoint interrupt registration

[Lorenzo Pieralisi]

On Fri, Oct 14, 2022 at 12:08:44AM +0530, Vidya Sagar wrote:
> Tegra PCIe endpoint has a common interrupt that notifies hardware events
> like link up, LTR send, etc. DMA completion event is also notified over
> this interrupt. Remove IRQF_ONESHOT flag from interrupt registration and
> allow DMA driver to share this interrupt.

Please give a clearer explanation of why this is safe and the reasoning
behind this change.

Lorenzo

> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
> ---
> V3:
> * This is a new patch in this series
> 
>  drivers/pci/controller/dwc/pcie-tegra194.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
> index 7820bf4b9786..786e5d5f43b9 100644
> --- a/drivers/pci/controller/dwc/pcie-tegra194.c
> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
> @@ -2354,7 +2354,7 @@ static int tegra_pcie_dw_probe(struct platform_device *pdev)
>  		ret = devm_request_threaded_irq(dev, pp->irq,
>  						tegra_pcie_ep_hard_irq,
>  						tegra_pcie_ep_irq_thread,
> -						IRQF_SHARED | IRQF_ONESHOT,
> +						IRQF_SHARED,
>  						"tegra-pcie-ep-intr", pcie);
>  		if (ret) {
>  			dev_err(dev, "Failed to request IRQ %d: %d\n", pp->irq,
> -- 
> 2.17.1
> 
> 
> -- 
> linux-phy mailing list
> linux-phy@lists.infradead.org
> https://lists.infradead.org/mailman/listinfo/linux-phy

Re: [PATCH V3 11/21] PCI: tegra194: Remove IRQF_ONESHOT flag during Endpoint interrupt registration

[Lorenzo Pieralisi]

On Fri, Oct 14, 2022 at 12:08:44AM +0530, Vidya Sagar wrote:
> Tegra PCIe endpoint has a common interrupt that notifies hardware events
> like link up, LTR send, etc. DMA completion event is also notified over
> this interrupt. Remove IRQF_ONESHOT flag from interrupt registration and
> allow DMA driver to share this interrupt.

I don't understand the rationale behind this change, please elaborate
on it.

Thanks,
Lorenzo

> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
> ---
> V3:
> * This is a new patch in this series
> 
>  drivers/pci/controller/dwc/pcie-tegra194.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
> index 7820bf4b9786..786e5d5f43b9 100644
> --- a/drivers/pci/controller/dwc/pcie-tegra194.c
> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
> @@ -2354,7 +2354,7 @@ static int tegra_pcie_dw_probe(struct platform_device *pdev)
>  		ret = devm_request_threaded_irq(dev, pp->irq,
>  						tegra_pcie_ep_hard_irq,
>  						tegra_pcie_ep_irq_thread,
> -						IRQF_SHARED | IRQF_ONESHOT,
> +						IRQF_SHARED,
>  						"tegra-pcie-ep-intr", pcie);
>  		if (ret) {
>  			dev_err(dev, "Failed to request IRQ %d: %d\n", pp->irq,
> -- 
> 2.17.1
> 
> 
> -- 
> linux-phy mailing list
> linux-phy@lists.infradead.org
> https://lists.infradead.org/mailman/listinfo/linux-phy

[PATCH V3 12/21] PCI: tegra194: Enable DMA interrupt

[Vidya Sagar]

Enable DMA interrupt to support Tegra PCIe DMA in both Root port and
Endpoint modes.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* This is a new patch in this series

 drivers/pci/controller/dwc/pcie-tegra194.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 786e5d5f43b9..a1c3481585c9 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -94,6 +94,7 @@
 #define APPL_INTR_EN_L1_8_0			0x44
 #define APPL_INTR_EN_L1_8_BW_MGT_INT_EN		BIT(2)
 #define APPL_INTR_EN_L1_8_AUTO_BW_INT_EN	BIT(3)
+#define APPL_INTR_EN_L1_8_EDMA_INT_EN		BIT(6)
 #define APPL_INTR_EN_L1_8_INTX_EN		BIT(11)
 #define APPL_INTR_EN_L1_8_AER_INT_EN		BIT(15)
 
@@ -552,6 +553,13 @@ static irqreturn_t tegra_pcie_ep_hard_irq(int irq, void *arg)
 		spurious = 0;
 	}
 
+	if (status_l0 & APPL_INTR_STATUS_L0_INT_INT) {
+		status_l1 = appl_readl(pcie, APPL_INTR_STATUS_L1_8_0);
+		/* Interrupt is handled by dma driver, don't treat it as spurious */
+		if (status_l1 & APPL_INTR_STATUS_L1_8_0_EDMA_INT_MASK)
+			spurious = 0;
+	}
+
 	if (spurious) {
 		dev_warn(pcie->dev, "Random interrupt (STATUS = 0x%08X)\n",
 			 status_l0);
@@ -781,6 +789,7 @@ static void tegra_pcie_enable_legacy_interrupts(struct dw_pcie_rp *pp)
 	val |= APPL_INTR_EN_L1_8_INTX_EN;
 	val |= APPL_INTR_EN_L1_8_AUTO_BW_INT_EN;
 	val |= APPL_INTR_EN_L1_8_BW_MGT_INT_EN;
+	val |= APPL_INTR_EN_L1_8_EDMA_INT_EN;
 	if (IS_ENABLED(CONFIG_PCIEAER))
 		val |= APPL_INTR_EN_L1_8_AER_INT_EN;
 	appl_writel(pcie, val, APPL_INTR_EN_L1_8_0);
@@ -1927,6 +1936,7 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
 	val |= APPL_INTR_EN_L0_0_SYS_INTR_EN;
 	val |= APPL_INTR_EN_L0_0_LINK_STATE_INT_EN;
 	val |= APPL_INTR_EN_L0_0_PCI_CMD_EN_INT_EN;
+	val |= APPL_INTR_EN_L0_0_INT_INT_EN;
 	appl_writel(pcie, val, APPL_INTR_EN_L0_0);
 
 	val = appl_readl(pcie, APPL_INTR_EN_L1_0_0);
@@ -1934,6 +1944,10 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
 	val |= APPL_INTR_EN_L1_0_0_RDLH_LINK_UP_INT_EN;
 	appl_writel(pcie, val, APPL_INTR_EN_L1_0_0);
 
+	val = appl_readl(pcie, APPL_INTR_EN_L1_8_0);
+	val |= APPL_INTR_EN_L1_8_EDMA_INT_EN;
+	appl_writel(pcie, val, APPL_INTR_EN_L1_8_0);
+
 	reset_control_deassert(pcie->core_rst);
 
 	val = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
-- 
2.17.1

[PATCH V3 13/21] PCI: tegra194: Enable hardware hot reset mode in Endpoint

[Vidya Sagar]

When PCIe link goes down, hardware can retrain the link and try to link up.
To enable this feature, program the APPL_CTRL register with hardware hot
reset with immediate LTSSM enable mode.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* This is a new patch in this series

 drivers/pci/controller/dwc/pcie-tegra194.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index a1c3481585c9..78ee0f713e71 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1913,6 +1913,8 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
 	val = appl_readl(pcie, APPL_CTRL);
 	val |= APPL_CTRL_SYS_PRE_DET_STATE;
 	val |= APPL_CTRL_HW_HOT_RST_EN;
+	val &= ~(APPL_CTRL_HW_HOT_RST_MODE_MASK << APPL_CTRL_HW_HOT_RST_MODE_SHIFT);
+	val |= (APPL_CTRL_HW_HOT_RST_MODE_IMDT_RST_LTSSM_EN << APPL_CTRL_HW_HOT_RST_MODE_SHIFT);
 	appl_writel(pcie, val, APPL_CTRL);
 
 	val = appl_readl(pcie, APPL_CFG_MISC);
-- 
2.17.1

[PATCH V3 14/21] PCI: tegra194: Allow system suspend when the Endpoint link is not up

[Vidya Sagar]

Only a Root port initiates the L2 sequence. PCIe link is kept in L2 state
during suspend. If Endpoint mode is enabled and the link is up, the
software cannot proceed with suspend. However, when the PCIe Endpoint
driver is probed, but the PCIe link is not up, Tegra can go into suspend
state. So, allow system to suspend in this case.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* This is a new patch in this series

 drivers/pci/controller/dwc/pcie-tegra194.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 78ee0f713e71..e6fd713e9868 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -2425,8 +2425,14 @@ static int tegra_pcie_dw_suspend_late(struct device *dev)
 	u32 val;
 
 	if (pcie->of_data->mode == DW_PCIE_EP_TYPE) {
-		dev_err(dev, "Failed to Suspend as Tegra PCIe is in EP mode\n");
-		return -EPERM;
+		disable_irq(pcie->pex_rst_irq);
+
+		if (pcie->ep_state == EP_STATE_ENABLED) {
+			dev_err(dev, "Tegra PCIe is in EP mode, suspend not allowed");
+			return -EPERM;
+		} else {
+			return 0;
+		}
 	}
 
 	if (!pcie->link_state && !pcie->slot_pluggable)
@@ -2448,6 +2454,9 @@ static int tegra_pcie_dw_suspend_noirq(struct device *dev)
 {
 	struct tegra_pcie_dw *pcie = dev_get_drvdata(dev);
 
+	if (pcie->of_data->mode == DW_PCIE_EP_TYPE)
+		return 0;
+
 	if (!pcie->link_state && !pcie->slot_pluggable)
 		return 0;
 
@@ -2463,6 +2472,9 @@ static int tegra_pcie_dw_resume_noirq(struct device *dev)
 	struct tegra_pcie_dw *pcie = dev_get_drvdata(dev);
 	int ret;
 
+	if (pcie->of_data->mode == DW_PCIE_EP_TYPE)
+		return 0;
+
 	if (!pcie->link_state && !pcie->slot_pluggable)
 		return 0;
 
@@ -2495,8 +2507,8 @@ static int tegra_pcie_dw_resume_early(struct device *dev)
 	u32 val;
 
 	if (pcie->of_data->mode == DW_PCIE_EP_TYPE) {
-		dev_err(dev, "Suspend is not supported in EP mode");
-		return -ENOTSUPP;
+		enable_irq(pcie->pex_rst_irq);
+		return 0;
 	}
 
 	if (!pcie->link_state && !pcie->slot_pluggable)
-- 
2.17.1

[PATCH V3 15/21] PCI: tegra194: Disable L1.2 capability of Tegra234 EP

[Vidya Sagar]

When Tegra234 is operating in the endpoint mode with L1.2 enabled, PCIe
link goes down during L1.2 exit. This is because Tegra234 is powering up
UPHY PLL immediately without making sure that the REFCLK is stable.
This is causing UPHY PLL to not lock to the correct frequency and leading
to link going down. There is no hardware fix for this, hence do not
advertise the L1.2 capability in the endpoint mode.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* This is a new patch in this series

 drivers/pci/controller/dwc/pcie-tegra194.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index e6fd713e9868..d592cf68b02c 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -246,6 +246,7 @@ struct tegra_pcie_dw_of_data {
 	bool has_sbr_reset_fix;
 	bool has_l1ss_exit_fix;
 	bool has_ltr_req_fix;
+	bool disable_l1_2;
 	u32 cdm_chk_int_en_bit;
 	u32 gen4_preset_vec;
 	u8 n_fts[2];
@@ -1967,10 +1968,11 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
 	init_host_aspm(pcie);
 
 	/* Disable ASPM-L1SS advertisement if there is no CLKREQ routing */
-	if (!pcie->supports_clkreq) {
+	if (!pcie->supports_clkreq)
 		disable_aspm_l11(pcie);
+
+	if (!pcie->supports_clkreq || pcie->of_data->disable_l1_2)
 		disable_aspm_l12(pcie);
-	}
 
 	if (!pcie->of_data->has_l1ss_exit_fix) {
 		val = dw_pcie_readl_dbi(pci, GEN3_RELATED_OFF);
@@ -2589,6 +2591,7 @@ static const struct tegra_pcie_dw_of_data tegra234_pcie_dw_ep_of_data = {
 	.mode = DW_PCIE_EP_TYPE,
 	.has_l1ss_exit_fix = true,
 	.has_ltr_req_fix = true,
+	.disable_l1_2 = true,
 	.cdm_chk_int_en_bit = BIT(18),
 	/* Gen4 - 6, 8 and 9 presets enabled */
 	.gen4_preset_vec = 0x340,
-- 
2.17.1

[PATCH V3 16/21] PCI: tegra194: Set LTR message request before PCIe link up

[Vidya Sagar]

LTR message should be sent as soon as the root port enables LTR in the
endpoint. Set snoop & no snoop LTR timing and LTR message request before
PCIe links up. This ensures that LTR message is sent upstream as soon as
LTR is enabled.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* This is a new patch in this series

 drivers/pci/controller/dwc/pcie-tegra194.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index d592cf68b02c..23ca97401339 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -493,11 +493,6 @@ static irqreturn_t tegra_pcie_ep_irq_thread(int irq, void *arg)
 	if (val & PCI_COMMAND_MASTER) {
 		ktime_t timeout;
 
-		/* 110us for both snoop and no-snoop */
-		val = 110 | (2 << PCI_LTR_SCALE_SHIFT) | LTR_MSG_REQ;
-		val |= (val << LTR_MST_NO_SNOOP_SHIFT);
-		appl_writel(pcie, val, APPL_LTR_MSG_1);
-
 		/* Send LTR upstream */
 		val = appl_readl(pcie, APPL_LTR_MSG_2);
 		val |= APPL_LTR_MSG_2_LTR_MSG_REQ_STATE;
@@ -1951,6 +1946,11 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
 	val |= APPL_INTR_EN_L1_8_EDMA_INT_EN;
 	appl_writel(pcie, val, APPL_INTR_EN_L1_8_0);
 
+	/* 110us for both snoop and no-snoop */
+	val = 110 | (2 << PCI_LTR_SCALE_SHIFT) | LTR_MSG_REQ;
+	val |= (val << LTR_MST_NO_SNOOP_SHIFT);
+	appl_writel(pcie, val, APPL_LTR_MSG_1);
+
 	reset_control_deassert(pcie->core_rst);
 
 	val = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
-- 
2.17.1

[PATCH V3 17/21] PCI: tegra194: Reduce AXI slave timeout value

[Vidya Sagar]

Reduce the AXI slave timeout value to 7ms to be in line with the CBB
logic's timeout value and to avoid CBB reporting errors because of no
response from the PCIe IPs AXI slave logic for configuration space accesses
through ECAM when the PCIe link is down. Also, set the Completion Timeout
value to Range-A: 1ms~10ms to be inline with the AXI timeout value.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* This is a new patch in this series

 drivers/pci/controller/dwc/pcie-tegra194.c | 24 ++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 23ca97401339..7890e0c0c0d2 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -198,6 +198,12 @@
 #define AMBA_ERROR_RESPONSE_CRS_OKAY_FFFFFFFF	1
 #define AMBA_ERROR_RESPONSE_CRS_OKAY_FFFF0001	2
 
+#define PORT_LOGIC_AMBA_LINK_TIMEOUT		0x8D4
+#define AMBA_LINK_TIMEOUT_PERIOD_MASK		GENMASK(7, 0)
+#define AMBA_LINK_TIMEOUT_PERIOD_VAL		0x7
+
+#define PCI_EXP_DEVCTL2_CPL_TO_VAL		0x2 /* Range-A: 1ms to 10ms */
+
 #define MSIX_ADDR_MATCH_LOW_OFF			0x940
 #define MSIX_ADDR_MATCH_LOW_OFF_EN		BIT(0)
 #define MSIX_ADDR_MATCH_LOW_OFF_MASK		GENMASK(31, 2)
@@ -922,6 +928,18 @@ static int tegra_pcie_dw_host_init(struct dw_pcie_rp *pp)
 		AMBA_ERROR_RESPONSE_CRS_SHIFT);
 	dw_pcie_writel_dbi(pci, PORT_LOGIC_AMBA_ERROR_RESPONSE_DEFAULT, val);
 
+	/* Reduce the AXI slave Timeout value to 7ms */
+	val  = dw_pcie_readl_dbi(pci, PORT_LOGIC_AMBA_LINK_TIMEOUT);
+	val &= ~AMBA_LINK_TIMEOUT_PERIOD_MASK;
+	val |= AMBA_LINK_TIMEOUT_PERIOD_VAL;
+	dw_pcie_writel_dbi(pci, PORT_LOGIC_AMBA_LINK_TIMEOUT, val);
+
+	/* Set the Completion Timeout value in 1ms~10ms range */
+	val_16  = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_DEVCTL2);
+	val_16 &= ~PCI_EXP_DEVCTL2_COMP_TIMEOUT;
+	val_16 |= PCI_EXP_DEVCTL2_CPL_TO_VAL;
+	dw_pcie_writew_dbi(pci, pcie->pcie_cap_base + PCI_EXP_DEVCTL2, val_16);
+
 	/* Configure Max lane width from DT */
 	val = dw_pcie_readl_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKCAP);
 	val &= ~PCI_EXP_LNKCAP_MLW;
@@ -1988,6 +2006,12 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
 	val_16 |= PCI_EXP_DEVCTL_PAYLOAD_256B;
 	dw_pcie_writew_dbi(pci, pcie->pcie_cap_base + PCI_EXP_DEVCTL, val_16);
 
+	/* Set the Completion Timeout value in 1ms~10ms range */
+	val_16  = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_DEVCTL2);
+	val_16 &= ~PCI_EXP_DEVCTL2_COMP_TIMEOUT;
+	val_16 |= PCI_EXP_DEVCTL2_CPL_TO_VAL;
+	dw_pcie_writew_dbi(pci, pcie->pcie_cap_base + PCI_EXP_DEVCTL2, val_16);
+
 	/* Clear Slot Clock Configuration bit if SRNS configuration */
 	if (pcie->enable_srns) {
 		val_16 = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base +
-- 
2.17.1

Re: [PATCH V3 17/21] PCI: tegra194: Reduce AXI slave timeout value

[Lorenzo Pieralisi]

On Fri, Oct 14, 2022 at 12:08:50AM +0530, Vidya Sagar wrote:
> Reduce the AXI slave timeout value to 7ms to be in line with the CBB

It would be good to understand where this 7ms delay comes from.

Please spell out what CBB is.

> logic's timeout value and to avoid CBB reporting errors because of no
> response from the PCIe IPs AXI slave logic for configuration space accesses
> through ECAM when the PCIe link is down. Also, set the Completion Timeout
> value to Range-A: 1ms~10ms to be inline with the AXI timeout value.
> 
> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
> ---
> V3:
> * This is a new patch in this series
> 
>  drivers/pci/controller/dwc/pcie-tegra194.c | 24 ++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
> index 23ca97401339..7890e0c0c0d2 100644
> --- a/drivers/pci/controller/dwc/pcie-tegra194.c
> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
> @@ -198,6 +198,12 @@
>  #define AMBA_ERROR_RESPONSE_CRS_OKAY_FFFFFFFF	1
>  #define AMBA_ERROR_RESPONSE_CRS_OKAY_FFFF0001	2
>  
> +#define PORT_LOGIC_AMBA_LINK_TIMEOUT		0x8D4
> +#define AMBA_LINK_TIMEOUT_PERIOD_MASK		GENMASK(7, 0)
> +#define AMBA_LINK_TIMEOUT_PERIOD_VAL		0x7
> +
> +#define PCI_EXP_DEVCTL2_CPL_TO_VAL		0x2 /* Range-A: 1ms to 10ms */
> +
>  #define MSIX_ADDR_MATCH_LOW_OFF			0x940
>  #define MSIX_ADDR_MATCH_LOW_OFF_EN		BIT(0)
>  #define MSIX_ADDR_MATCH_LOW_OFF_MASK		GENMASK(31, 2)
> @@ -922,6 +928,18 @@ static int tegra_pcie_dw_host_init(struct dw_pcie_rp *pp)
>  		AMBA_ERROR_RESPONSE_CRS_SHIFT);
>  	dw_pcie_writel_dbi(pci, PORT_LOGIC_AMBA_ERROR_RESPONSE_DEFAULT, val);
>  
> +	/* Reduce the AXI slave Timeout value to 7ms */
> +	val  = dw_pcie_readl_dbi(pci, PORT_LOGIC_AMBA_LINK_TIMEOUT);
> +	val &= ~AMBA_LINK_TIMEOUT_PERIOD_MASK;
> +	val |= AMBA_LINK_TIMEOUT_PERIOD_VAL;
> +	dw_pcie_writel_dbi(pci, PORT_LOGIC_AMBA_LINK_TIMEOUT, val);
> +
> +	/* Set the Completion Timeout value in 1ms~10ms range */
> +	val_16  = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_DEVCTL2);
> +	val_16 &= ~PCI_EXP_DEVCTL2_COMP_TIMEOUT;
> +	val_16 |= PCI_EXP_DEVCTL2_CPL_TO_VAL;
> +	dw_pcie_writew_dbi(pci, pcie->pcie_cap_base + PCI_EXP_DEVCTL2, val_16);
> +
>  	/* Configure Max lane width from DT */
>  	val = dw_pcie_readl_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKCAP);
>  	val &= ~PCI_EXP_LNKCAP_MLW;
> @@ -1988,6 +2006,12 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
>  	val_16 |= PCI_EXP_DEVCTL_PAYLOAD_256B;
>  	dw_pcie_writew_dbi(pci, pcie->pcie_cap_base + PCI_EXP_DEVCTL, val_16);
>  
> +	/* Set the Completion Timeout value in 1ms~10ms range */
> +	val_16  = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_DEVCTL2);
> +	val_16 &= ~PCI_EXP_DEVCTL2_COMP_TIMEOUT;
> +	val_16 |= PCI_EXP_DEVCTL2_CPL_TO_VAL;
> +	dw_pcie_writew_dbi(pci, pcie->pcie_cap_base + PCI_EXP_DEVCTL2, val_16);
> +
>  	/* Clear Slot Clock Configuration bit if SRNS configuration */
>  	if (pcie->enable_srns) {
>  		val_16 = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base +
> -- 
> 2.17.1
> 
> 
> -- 
> linux-phy mailing list
> linux-phy@lists.infradead.org
> https://lists.infradead.org/mailman/listinfo/linux-phy

[PATCH V3 18/21] PCI: tegra194: Don't force the device into the D0 state before L2

[Vidya Sagar]

As per PCIe CEM spec rev 4.0 ver 1.0 sec 2.3, the PCIe endpoint device
should be in D3 state to assert wake# pin. This takes precedence over PCI
Express Base r4.0 v1.0 September 27-2017, 5.2 Link State Power Management
which states that the device can be put into D0 state before taking the
link to L2 state. So, to enable the wake functionality for endpoints, do
not force the devices to D0 state before taking the link to L2 state.
There is no functional issue with the endpoints where the link doesn't go
into L2 state (the reason why the earlier change was made in the first
place) as the root port proceeds with the usual flow post PME timeout.

Fixes: 56e15a238d92 ("PCI: tegra: Add Tegra194 PCIe support")
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* This is a new patch in this series

 drivers/pci/controller/dwc/pcie-tegra194.c | 41 ----------------------
 1 file changed, 41 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 7890e0c0c0d2..3baf1a26fe68 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1358,44 +1358,6 @@ static int tegra_pcie_bpmp_set_pll_state(struct tegra_pcie_dw *pcie,
 	return 0;
 }
 
-static void tegra_pcie_downstream_dev_to_D0(struct tegra_pcie_dw *pcie)
-{
-	struct dw_pcie_rp *pp = &pcie->pci.pp;
-	struct pci_bus *child, *root_bus = NULL;
-	struct pci_dev *pdev;
-
-	/*
-	 * link doesn't go into L2 state with some of the endpoints with Tegra
-	 * if they are not in D0 state. So, need to make sure that immediate
-	 * downstream devices are in D0 state before sending PME_TurnOff to put
-	 * link into L2 state.
-	 * This is as per PCI Express Base r4.0 v1.0 September 27-2017,
-	 * 5.2 Link State Power Management (Page #428).
-	 */
-
-	list_for_each_entry(child, &pp->bridge->bus->children, node) {
-		/* Bring downstream devices to D0 if they are not already in */
-		if (child->parent == pp->bridge->bus) {
-			root_bus = child;
-			break;
-		}
-	}
-
-	if (!root_bus) {
-		dev_err(pcie->dev, "Failed to find downstream devices\n");
-		return;
-	}
-
-	list_for_each_entry(pdev, &root_bus->devices, bus_list) {
-		if (PCI_SLOT(pdev->devfn) == 0) {
-			if (pci_set_power_state(pdev, PCI_D0))
-				dev_err(pcie->dev,
-					"Failed to transition %s to D0 state\n",
-					dev_name(&pdev->dev));
-		}
-	}
-}
-
 static int tegra_pcie_get_slot_regulators(struct tegra_pcie_dw *pcie)
 {
 	pcie->slot_ctl_3v3 = devm_regulator_get_optional(pcie->dev, "vpcie3v3");
@@ -1725,7 +1687,6 @@ static void tegra_pcie_dw_pme_turnoff(struct tegra_pcie_dw *pcie)
 
 static void tegra_pcie_deinit_controller(struct tegra_pcie_dw *pcie)
 {
-	tegra_pcie_downstream_dev_to_D0(pcie);
 	dw_pcie_host_deinit(&pcie->pci.pp);
 	tegra_pcie_dw_pme_turnoff(pcie);
 	tegra_pcie_unconfig_controller(pcie);
@@ -2486,7 +2447,6 @@ static int tegra_pcie_dw_suspend_noirq(struct device *dev)
 	if (!pcie->link_state && !pcie->slot_pluggable)
 		return 0;
 
-	tegra_pcie_downstream_dev_to_D0(pcie);
 	tegra_pcie_dw_pme_turnoff(pcie);
 	tegra_pcie_unconfig_controller(pcie);
 
@@ -2565,7 +2525,6 @@ static void tegra_pcie_dw_shutdown(struct platform_device *pdev)
 		if (pcie->slot_pluggable)
 			unregister_gpio_hotplug_slot(&pcie->hp_slot);
 		debugfs_remove_recursive(pcie->debugfs);
-		tegra_pcie_downstream_dev_to_D0(pcie);
 
 		disable_irq(pcie->pci.pp.irq);
 		if (IS_ENABLED(CONFIG_PCI_MSI))
-- 
2.17.1

[PATCH V3 19/21] PCI: tegra194: Free up EP resources during remove()

[Vidya Sagar]

Free up the resources during remove() that were acquired by the DesignWare
driver for the endpoint mode during proble().

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* This is a new patch in this series

 drivers/pci/controller/dwc/pcie-tegra194.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 3baf1a26fe68..c88c36d85ee5 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -2383,6 +2383,7 @@ static int tegra_pcie_dw_probe(struct platform_device *pdev)
 static int tegra_pcie_dw_remove(struct platform_device *pdev)
 {
 	struct tegra_pcie_dw *pcie = platform_get_drvdata(pdev);
+	struct dw_pcie_ep *ep = &pcie->pci.ep;
 
 	if (pcie->of_data->mode == DW_PCIE_RC_TYPE) {
 		if (!pcie->link_state && !pcie->slot_pluggable)
@@ -2396,6 +2397,7 @@ static int tegra_pcie_dw_remove(struct platform_device *pdev)
 	} else {
 		disable_irq(pcie->pex_rst_irq);
 		pex_ep_event_pex_rst_assert(pcie);
+		dw_pcie_ep_exit(ep);
 	}
 
 	pm_runtime_disable(pcie->dev);
-- 
2.17.1

Re: [PATCH V3 19/21] PCI: tegra194: Free up EP resources during remove()

[Lorenzo Pieralisi]

On Fri, Oct 14, 2022 at 12:08:52AM +0530, Vidya Sagar wrote:
> Free up the resources during remove() that were acquired by the DesignWare
> driver for the endpoint mode during proble().

s/proble/probe

> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
> ---
> V3:
> * This is a new patch in this series
> 
>  drivers/pci/controller/dwc/pcie-tegra194.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
> index 3baf1a26fe68..c88c36d85ee5 100644
> --- a/drivers/pci/controller/dwc/pcie-tegra194.c
> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
> @@ -2383,6 +2383,7 @@ static int tegra_pcie_dw_probe(struct platform_device *pdev)
>  static int tegra_pcie_dw_remove(struct platform_device *pdev)
>  {
>  	struct tegra_pcie_dw *pcie = platform_get_drvdata(pdev);
> +	struct dw_pcie_ep *ep = &pcie->pci.ep;
>  
>  	if (pcie->of_data->mode == DW_PCIE_RC_TYPE) {
>  		if (!pcie->link_state && !pcie->slot_pluggable)
> @@ -2396,6 +2397,7 @@ static int tegra_pcie_dw_remove(struct platform_device *pdev)
>  	} else {
>  		disable_irq(pcie->pex_rst_irq);
>  		pex_ep_event_pex_rst_assert(pcie);
> +		dw_pcie_ep_exit(ep);
>  	}
>  
>  	pm_runtime_disable(pcie->dev);
> -- 
> 2.17.1
> 
> 
> -- 
> linux-phy mailing list
> linux-phy@lists.infradead.org
> https://lists.infradead.org/mailman/listinfo/linux-phy

[PATCH V3 20/21] dt-bindings: PCI: tegra194: Add monitor clock support

[Vidya Sagar]

Tegra supports PCIe core clock monitoring for any rate changes that may be
happening because of the link speed changes. This is useful in tracking
any changes in the core clock that are not initiated by the software.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* This is a new patch in this series

 .../devicetree/bindings/pci/nvidia,tegra194-pcie-ep.yaml    | 6 +++++-
 .../devicetree/bindings/pci/nvidia,tegra194-pcie.yaml       | 6 +++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/pci/nvidia,tegra194-pcie-ep.yaml b/Documentation/devicetree/bindings/pci/nvidia,tegra194-pcie-ep.yaml
index a24fb8307d29..7c6900802f04 100644
--- a/Documentation/devicetree/bindings/pci/nvidia,tegra194-pcie-ep.yaml
+++ b/Documentation/devicetree/bindings/pci/nvidia,tegra194-pcie-ep.yaml
@@ -55,12 +55,16 @@ properties:
       - const: intr
 
   clocks:
+    minItems: 1
     items:
-      - description: module clock
+      - description: module's core clock
+      - description: module's monitor clock
 
   clock-names:
+    minItems: 1
     items:
       - const: core
+      - const: core_m
 
   resets:
     items:
diff --git a/Documentation/devicetree/bindings/pci/nvidia,tegra194-pcie.yaml b/Documentation/devicetree/bindings/pci/nvidia,tegra194-pcie.yaml
index 75da3e8eecb9..aaaa238e6dc1 100644
--- a/Documentation/devicetree/bindings/pci/nvidia,tegra194-pcie.yaml
+++ b/Documentation/devicetree/bindings/pci/nvidia,tegra194-pcie.yaml
@@ -54,12 +54,16 @@ properties:
       - const: msi
 
   clocks:
+    minItems: 1
     items:
-      - description: module clock
+      - description: module's core clock
+      - description: module's monitor clock
 
   clock-names:
+    minItems: 1
     items:
       - const: core
+      - const: core_m
 
   resets:
     items:
-- 
2.17.1

[PATCH V3 21/21] PCI: tegra194: Add core monitor clock support

[Vidya Sagar]

Tegra supports PCIe core clock monitoring for any rate changes that may be
happening because of the link speed changes. This is useful in tracking
any changes in the core clock that are not initiated by the software. This
patch adds support to parse the monitor clock info from device-tree and
enable it if present.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V3:
* This is a new patch in this series

 drivers/pci/controller/dwc/pcie-tegra194.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index c88c36d85ee5..28512dc60172 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -265,6 +265,7 @@ struct tegra_pcie_dw {
 	struct resource *atu_dma_res;
 	void __iomem *appl_base;
 	struct clk *core_clk;
+	struct clk *core_clk_m;
 	struct reset_control *core_apb_rst;
 	struct reset_control *core_rst;
 	struct dw_pcie pci;
@@ -978,6 +979,8 @@ static int tegra_pcie_dw_host_init(struct dw_pcie_rp *pp)
 	}
 
 	clk_set_rate(pcie->core_clk, GEN4_CORE_CLK_FREQ);
+	if (clk_prepare_enable(pcie->core_clk_m))
+		dev_err(pci->dev, "Failed to enable core monitor clock\n");
 
 	return 0;
 }
@@ -1050,6 +1053,12 @@ static int tegra_pcie_dw_start_link(struct dw_pcie *pci)
 		val &= ~PCI_DLF_EXCHANGE_ENABLE;
 		dw_pcie_writel_dbi(pci, offset + PCI_DLF_CAP, val);
 
+		/*
+		 * core_clk_m is enabled as part of host_init callback in
+		 * dw_pcie_host_init(). Disable the clock since below
+		 * tegra_pcie_dw_host_init() will enable it again.
+		 */
+		clk_disable_unprepare(pcie->core_clk_m);
 		tegra_pcie_dw_host_init(pp);
 		dw_pcie_setup_rc(pp);
 
@@ -1059,7 +1068,8 @@ static int tegra_pcie_dw_start_link(struct dw_pcie *pci)
 
 	speed = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKSTA) &
 		PCI_EXP_LNKSTA_CLS;
-	clk_set_rate(pcie->core_clk, pcie_gen_freq[speed - 1]);
+	if (!pcie->core_clk_m)
+		clk_set_rate(pcie->core_clk, pcie_gen_freq[speed - 1]);
 
 	tegra_pcie_enable_interrupts(pp);
 
@@ -1687,6 +1697,7 @@ static void tegra_pcie_dw_pme_turnoff(struct tegra_pcie_dw *pcie)
 
 static void tegra_pcie_deinit_controller(struct tegra_pcie_dw *pcie)
 {
+	clk_disable_unprepare(pcie->core_clk_m);
 	dw_pcie_host_deinit(&pcie->pci.pp);
 	tegra_pcie_dw_pme_turnoff(pcie);
 	tegra_pcie_unconfig_controller(pcie);
@@ -2266,6 +2277,13 @@ static int tegra_pcie_dw_probe(struct platform_device *pdev)
 		return PTR_ERR(pcie->core_clk);
 	}
 
+	pcie->core_clk_m = devm_clk_get_optional(dev, "core_m");
+	if (IS_ERR(pcie->core_clk_m)) {
+		dev_err(dev, "Failed to get monitor clock: %ld\n",
+			PTR_ERR(pcie->core_clk_m));
+		return PTR_ERR(pcie->core_clk_m);
+	}
+
 	pcie->appl_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
 						      "appl");
 	if (!pcie->appl_res) {
@@ -2449,6 +2467,7 @@ static int tegra_pcie_dw_suspend_noirq(struct device *dev)
 	if (!pcie->link_state && !pcie->slot_pluggable)
 		return 0;
 
+	clk_disable_unprepare(pcie->core_clk_m);
 	tegra_pcie_dw_pme_turnoff(pcie);
 	tegra_pcie_unconfig_controller(pcie);
 
-- 
2.17.1