[PATCH v2 0/6] PCI: dwc: Revert Link Up IRQ support

[PATCH v2 0/6] PCI: dwc: Revert Link Up IRQ support

[Niklas Cassel]

Revert all patches related to pcie-designware Root Complex Link Up IRQ
support.

While this fake hotplugging was a nice idea, it has shown that this feature
does not handle PCIe switches correctly:
pci_bus 0004:43: busn_res: can not insert [bus 43-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci_bus 0004:43: busn_res: [bus 43-41] end is updated to 43
pci_bus 0004:43: busn_res: can not insert [bus 43] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci 0004:42:00.0: devices behind bridge are unusable because [bus 43] cannot be assigned for them
pci_bus 0004:44: busn_res: can not insert [bus 44-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci_bus 0004:44: busn_res: [bus 44-41] end is updated to 44
pci_bus 0004:44: busn_res: can not insert [bus 44] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci 0004:42:02.0: devices behind bridge are unusable because [bus 44] cannot be assigned for them
pci_bus 0004:45: busn_res: can not insert [bus 45-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci_bus 0004:45: busn_res: [bus 45-41] end is updated to 45
pci_bus 0004:45: busn_res: can not insert [bus 45] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci 0004:42:06.0: devices behind bridge are unusable because [bus 45] cannot be assigned for them
pci_bus 0004:46: busn_res: can not insert [bus 46-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci_bus 0004:46: busn_res: [bus 46-41] end is updated to 46
pci_bus 0004:46: busn_res: can not insert [bus 46] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci 0004:42:0e.0: devices behind bridge are unusable because [bus 46] cannot be assigned for them
pci_bus 0004:42: busn_res: [bus 42-41] end is updated to 46
pci_bus 0004:42: busn_res: can not insert [bus 42-46] under [bus 41] (conflicts with (null) [bus 41])
pci 0004:41:00.0: devices behind bridge are unusable because [bus 42-46] cannot be assigned for them
pcieport 0004:40:00.0: bridge has subordinate 41 but max busn 46

During the initial scan, PCI core doesn't see the switch and since the Root
Port is not hot plug capable, the secondary bus number gets assigned as the
subordinate bus number. This means, the PCI core assumes that only one bus
will appear behind the Root Port since the Root Port is not hot plug
capable.

This works perfectly fine for PCIe endpoints connected to the Root Port,
since they don't extend the bus. However, if a PCIe switch is connected,
then there is a problem when the downstream busses starts showing up and
the PCI core doesn't extend the subordinate bus number after initial scan
during boot.

The long term plan is to migrate this driver to the pwrctrl framework,
once it adds proper support for powering up and enumerating PCIe switches.


Changes since v1:
-Rebased against latest pci/controller/dwc
-Picked up tags.


Niklas Cassel (6):
  Revert "PCI: dw-rockchip: Don't wait for link since we can detect Link
    Up"
  Revert "PCI: dw-rockchip: Enumerate endpoints based on dll_link_up
    IRQ"
  Revert "PCI: qcom: Don't wait for link if we can detect Link Up"
  Revert "PCI: qcom: Enable MSI interrupts together with Link up if
    'Global IRQ' is supported"
  Revert "PCI: qcom: Enumerate endpoints based on Link up event in
    'global_irq' interrupt"
  Revert "PCI: dwc: Don't wait for link up if driver can detect Link Up
    event"

 .../pci/controller/dwc/pcie-designware-host.c | 10 +--
 drivers/pci/controller/dwc/pcie-designware.h  |  1 -
 drivers/pci/controller/dwc/pcie-dw-rockchip.c | 60 +-----------------
 drivers/pci/controller/dwc/pcie-qcom.c        | 63 +------------------
 4 files changed, 6 insertions(+), 128 deletions(-)


base-commit: cfd2fdfd0a8da2e5bbfdc4009b9c4b8bf164c937
-- 
2.52.0

[PATCH v2 1/6] Revert "PCI: dw-rockchip: Don't wait for link since we can detect Link Up"

[Niklas Cassel]

This reverts commit ec9fd499b9c60a187ac8d6414c3c343c77d32e42.

While this fake hotplugging was a nice idea, it has shown that this feature
does not handle PCIe switches correctly:
pci_bus 0004:43: busn_res: can not insert [bus 43-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci_bus 0004:43: busn_res: [bus 43-41] end is updated to 43
pci_bus 0004:43: busn_res: can not insert [bus 43] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci 0004:42:00.0: devices behind bridge are unusable because [bus 43] cannot be assigned for them
pci_bus 0004:44: busn_res: can not insert [bus 44-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci_bus 0004:44: busn_res: [bus 44-41] end is updated to 44
pci_bus 0004:44: busn_res: can not insert [bus 44] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci 0004:42:02.0: devices behind bridge are unusable because [bus 44] cannot be assigned for them
pci_bus 0004:45: busn_res: can not insert [bus 45-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci_bus 0004:45: busn_res: [bus 45-41] end is updated to 45
pci_bus 0004:45: busn_res: can not insert [bus 45] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci 0004:42:06.0: devices behind bridge are unusable because [bus 45] cannot be assigned for them
pci_bus 0004:46: busn_res: can not insert [bus 46-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci_bus 0004:46: busn_res: [bus 46-41] end is updated to 46
pci_bus 0004:46: busn_res: can not insert [bus 46] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci 0004:42:0e.0: devices behind bridge are unusable because [bus 46] cannot be assigned for them
pci_bus 0004:42: busn_res: [bus 42-41] end is updated to 46
pci_bus 0004:42: busn_res: can not insert [bus 42-46] under [bus 41] (conflicts with (null) [bus 41])
pci 0004:41:00.0: devices behind bridge are unusable because [bus 42-46] cannot be assigned for them
pcieport 0004:40:00.0: bridge has subordinate 41 but max busn 46

During the initial scan, PCI core doesn't see the switch and since the Root
Port is not hot plug capable, the secondary bus number gets assigned as the
subordinate bus number. This means, the PCI core assumes that only one bus
will appear behind the Root Port since the Root Port is not hot plug
capable.

This works perfectly fine for PCIe endpoints connected to the Root Port,
since they don't extend the bus. However, if a PCIe switch is connected,
then there is a problem when the downstream busses starts showing up and
the PCI core doesn't extend the subordinate bus number after initial scan
during boot.

The long term plan is to migrate this driver to the pwrctrl framework,
once it adds proper support for powering up and enumerating PCIe switches.

Cc: stable@vger.kernel.org
Suggested-by: Manivannan Sadhasivam <mani@kernel.org>
Acked-by: Shawn Lin <shawn.lin@rock-chips.com>
Tested-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Niklas Cassel <cassel@kernel.org>
---
 drivers/pci/controller/dwc/pcie-dw-rockchip.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
index 8c1c92208802..ca808d8f7975 100644
--- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c
+++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
@@ -601,7 +601,6 @@ static int rockchip_pcie_configure_rc(struct platform_device *pdev,
 
 	pp = &rockchip->pci.pp;
 	pp->ops = &rockchip_pcie_host_ops;
-	pp->use_linkup_irq = true;
 
 	ret = dw_pcie_host_init(pp);
 	if (ret) {
-- 
2.52.0

[PATCH v2 2/6] Revert "PCI: dw-rockchip: Enumerate endpoints based on dll_link_up IRQ"

[Niklas Cassel]

This reverts commit 0e0b45ab5d770a748487ba0ae8f77d1fb0f0de3e.

While this fake hotplugging was a nice idea, it has shown that this feature
does not handle PCIe switches correctly:
pci_bus 0004:43: busn_res: can not insert [bus 43-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci_bus 0004:43: busn_res: [bus 43-41] end is updated to 43
pci_bus 0004:43: busn_res: can not insert [bus 43] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci 0004:42:00.0: devices behind bridge are unusable because [bus 43] cannot be assigned for them
pci_bus 0004:44: busn_res: can not insert [bus 44-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci_bus 0004:44: busn_res: [bus 44-41] end is updated to 44
pci_bus 0004:44: busn_res: can not insert [bus 44] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci 0004:42:02.0: devices behind bridge are unusable because [bus 44] cannot be assigned for them
pci_bus 0004:45: busn_res: can not insert [bus 45-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci_bus 0004:45: busn_res: [bus 45-41] end is updated to 45
pci_bus 0004:45: busn_res: can not insert [bus 45] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci 0004:42:06.0: devices behind bridge are unusable because [bus 45] cannot be assigned for them
pci_bus 0004:46: busn_res: can not insert [bus 46-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci_bus 0004:46: busn_res: [bus 46-41] end is updated to 46
pci_bus 0004:46: busn_res: can not insert [bus 46] under [bus 42-41] (conflicts with (null) [bus 42-41])
pci 0004:42:0e.0: devices behind bridge are unusable because [bus 46] cannot be assigned for them
pci_bus 0004:42: busn_res: [bus 42-41] end is updated to 46
pci_bus 0004:42: busn_res: can not insert [bus 42-46] under [bus 41] (conflicts with (null) [bus 41])
pci 0004:41:00.0: devices behind bridge are unusable because [bus 42-46] cannot be assigned for them
pcieport 0004:40:00.0: bridge has subordinate 41 but max busn 46

During the initial scan, PCI core doesn't see the switch and since the Root
Port is not hot plug capable, the secondary bus number gets assigned as the
subordinate bus number. This means, the PCI core assumes that only one bus
will appear behind the Root Port since the Root Port is not hot plug
capable.

This works perfectly fine for PCIe endpoints connected to the Root Port,
since they don't extend the bus. However, if a PCIe switch is connected,
then there is a problem when the downstream busses starts showing up and
the PCI core doesn't extend the subordinate bus number after initial scan
during boot.

The long term plan is to migrate this driver to the pwrctrl framework,
once it adds proper support for powering up and enumerating PCIe switches.

Cc: stable@vger.kernel.org
Suggested-by: Manivannan Sadhasivam <mani@kernel.org>
Acked-by: Shawn Lin <shawn.lin@rock-chips.com>
Tested-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Niklas Cassel <cassel@kernel.org>
---
 drivers/pci/controller/dwc/pcie-dw-rockchip.c | 59 +------------------
 1 file changed, 3 insertions(+), 56 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
index ca808d8f7975..352f513ebf03 100644
--- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c
+++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
@@ -508,34 +508,6 @@ static const struct dw_pcie_ops dw_pcie_ops = {
 	.get_ltssm = rockchip_pcie_get_ltssm,
 };
 
-static irqreturn_t rockchip_pcie_rc_sys_irq_thread(int irq, void *arg)
-{
-	struct rockchip_pcie *rockchip = arg;
-	struct dw_pcie *pci = &rockchip->pci;
-	struct dw_pcie_rp *pp = &pci->pp;
-	struct device *dev = pci->dev;
-	u32 reg;
-
-	reg = rockchip_pcie_readl_apb(rockchip, PCIE_CLIENT_INTR_STATUS_MISC);
-	rockchip_pcie_writel_apb(rockchip, reg, PCIE_CLIENT_INTR_STATUS_MISC);
-
-	dev_dbg(dev, "PCIE_CLIENT_INTR_STATUS_MISC: %#x\n", reg);
-	dev_dbg(dev, "LTSSM_STATUS: %#x\n", rockchip_pcie_get_ltssm_reg(rockchip));
-
-	if (reg & PCIE_RDLH_LINK_UP_CHGED) {
-		if (rockchip_pcie_link_up(pci)) {
-			msleep(PCIE_RESET_CONFIG_WAIT_MS);
-			dev_dbg(dev, "Received Link up event. Starting enumeration!\n");
-			/* Rescan the bus to enumerate endpoint devices */
-			pci_lock_rescan_remove();
-			pci_rescan_bus(pp->bridge->bus);
-			pci_unlock_rescan_remove();
-		}
-	}
-
-	return IRQ_HANDLED;
-}
-
 static irqreturn_t rockchip_pcie_ep_sys_irq_thread(int irq, void *arg)
 {
 	struct rockchip_pcie *rockchip = arg;
@@ -568,29 +540,14 @@ static irqreturn_t rockchip_pcie_ep_sys_irq_thread(int irq, void *arg)
 	return IRQ_HANDLED;
 }
 
-static int rockchip_pcie_configure_rc(struct platform_device *pdev,
-				      struct rockchip_pcie *rockchip)
+static int rockchip_pcie_configure_rc(struct rockchip_pcie *rockchip)
 {
-	struct device *dev = &pdev->dev;
 	struct dw_pcie_rp *pp;
-	int irq, ret;
 	u32 val;
 
 	if (!IS_ENABLED(CONFIG_PCIE_ROCKCHIP_DW_HOST))
 		return -ENODEV;
 
-	irq = platform_get_irq_byname(pdev, "sys");
-	if (irq < 0)
-		return irq;
-
-	ret = devm_request_threaded_irq(dev, irq, NULL,
-					rockchip_pcie_rc_sys_irq_thread,
-					IRQF_ONESHOT, "pcie-sys-rc", rockchip);
-	if (ret) {
-		dev_err(dev, "failed to request PCIe sys IRQ\n");
-		return ret;
-	}
-
 	/* LTSSM enable control mode */
 	val = FIELD_PREP_WM16(PCIE_LTSSM_ENABLE_ENHANCE, 1);
 	rockchip_pcie_writel_apb(rockchip, val, PCIE_CLIENT_HOT_RESET_CTRL);
@@ -602,17 +559,7 @@ static int rockchip_pcie_configure_rc(struct platform_device *pdev,
 	pp = &rockchip->pci.pp;
 	pp->ops = &rockchip_pcie_host_ops;
 
-	ret = dw_pcie_host_init(pp);
-	if (ret) {
-		dev_err(dev, "failed to initialize host\n");
-		return ret;
-	}
-
-	/* unmask DLL up/down indicator */
-	val = FIELD_PREP_WM16(PCIE_RDLH_LINK_UP_CHGED, 0);
-	rockchip_pcie_writel_apb(rockchip, val, PCIE_CLIENT_INTR_MASK_MISC);
-
-	return ret;
+	return dw_pcie_host_init(pp);
 }
 
 static int rockchip_pcie_configure_ep(struct platform_device *pdev,
@@ -731,7 +678,7 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
 
 	switch (data->mode) {
 	case DW_PCIE_RC_TYPE:
-		ret = rockchip_pcie_configure_rc(pdev, rockchip);
+		ret = rockchip_pcie_configure_rc(rockchip);
 		if (ret)
 			goto deinit_clk;
 		break;
-- 
2.52.0

Re: [PATCH v2 0/6] PCI: dwc: Revert Link Up IRQ support

[Manivannan Sadhasivam]

On Mon, 22 Dec 2025 07:42:07 +0100, Niklas Cassel wrote:
> Revert all patches related to pcie-designware Root Complex Link Up IRQ
> support.
> 
> While this fake hotplugging was a nice idea, it has shown that this feature
> does not handle PCIe switches correctly:
> pci_bus 0004:43: busn_res: can not insert [bus 43-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
> pci_bus 0004:43: busn_res: [bus 43-41] end is updated to 43
> pci_bus 0004:43: busn_res: can not insert [bus 43] under [bus 42-41] (conflicts with (null) [bus 42-41])
> pci 0004:42:00.0: devices behind bridge are unusable because [bus 43] cannot be assigned for them
> pci_bus 0004:44: busn_res: can not insert [bus 44-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
> pci_bus 0004:44: busn_res: [bus 44-41] end is updated to 44
> pci_bus 0004:44: busn_res: can not insert [bus 44] under [bus 42-41] (conflicts with (null) [bus 42-41])
> pci 0004:42:02.0: devices behind bridge are unusable because [bus 44] cannot be assigned for them
> pci_bus 0004:45: busn_res: can not insert [bus 45-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
> pci_bus 0004:45: busn_res: [bus 45-41] end is updated to 45
> pci_bus 0004:45: busn_res: can not insert [bus 45] under [bus 42-41] (conflicts with (null) [bus 42-41])
> pci 0004:42:06.0: devices behind bridge are unusable because [bus 45] cannot be assigned for them
> pci_bus 0004:46: busn_res: can not insert [bus 46-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
> pci_bus 0004:46: busn_res: [bus 46-41] end is updated to 46
> pci_bus 0004:46: busn_res: can not insert [bus 46] under [bus 42-41] (conflicts with (null) [bus 42-41])
> pci 0004:42:0e.0: devices behind bridge are unusable because [bus 46] cannot be assigned for them
> pci_bus 0004:42: busn_res: [bus 42-41] end is updated to 46
> pci_bus 0004:42: busn_res: can not insert [bus 42-46] under [bus 41] (conflicts with (null) [bus 41])
> pci 0004:41:00.0: devices behind bridge are unusable because [bus 42-46] cannot be assigned for them
> pcieport 0004:40:00.0: bridge has subordinate 41 but max busn 46
> 
> [...]

Applied, thanks!

[1/6] Revert "PCI: dw-rockchip: Don't wait for link since we can detect Link Up"
      commit: fc6298086bfacaa7003b0bd1da4e4f42b29f7d77
[2/6] Revert "PCI: dw-rockchip: Enumerate endpoints based on dll_link_up IRQ"
      commit: 180c3cfe36786d261a55da52a161f9e279b19a6f
[3/6] Revert "PCI: qcom: Don't wait for link if we can detect Link Up"
      commit: e9ce5b3804436301ab343bc14203a4c14b336d1b
[4/6] Revert "PCI: qcom: Enable MSI interrupts together with Link up if 'Global IRQ' is supported"
      commit: 7ebdefb87942073679e56cfbc5a72e8fc5441bfc
[5/6] Revert "PCI: qcom: Enumerate endpoints based on Link up event in 'global_irq' interrupt"
      commit: 9a9793b55854422652ea92625e48277c4651c0fd
[6/6] Revert "PCI: dwc: Don't wait for link up if driver can detect Link Up event"
      commit: 142d5869f6eec3110adda0ad2d931f5b3c22371d

Best regards,
-- 
Manivannan Sadhasivam <mani@kernel.org>

Re: [PATCH v2 1/6] Revert "PCI: dw-rockchip: Don't wait for link since we can detect Link Up"

[Bjorn Helgaas]

[+cc Ilpo]

On Mon, Dec 22, 2025 at 07:42:08AM +0100, Niklas Cassel wrote:
> This reverts commit ec9fd499b9c60a187ac8d6414c3c343c77d32e42.
> 
> While this fake hotplugging was a nice idea, it has shown that this feature
> does not handle PCIe switches correctly:
> pci_bus 0004:43: busn_res: can not insert [bus 43-41] under [bus 42-41] (conflicts with (null) [bus 42-41])

Apart from the actual problem you're fixing, it looks like some of our
bus number resource setup is a little deficient here.  The "43-41" and
"42-41" ranges are bogus and "(null)" doesn't tell us anything useful.

> pci_bus 0004:43: busn_res: [bus 43-41] end is updated to 43
> pci_bus 0004:43: busn_res: can not insert [bus 43] under [bus 42-41] (conflicts with (null) [bus 42-41])
> pci 0004:42:00.0: devices behind bridge are unusable because [bus 43] cannot be assigned for them
> pci_bus 0004:44: busn_res: can not insert [bus 44-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
> pci_bus 0004:44: busn_res: [bus 44-41] end is updated to 44
> pci_bus 0004:44: busn_res: can not insert [bus 44] under [bus 42-41] (conflicts with (null) [bus 42-41])
> pci 0004:42:02.0: devices behind bridge are unusable because [bus 44] cannot be assigned for them
> pci_bus 0004:45: busn_res: can not insert [bus 45-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
> pci_bus 0004:45: busn_res: [bus 45-41] end is updated to 45
> pci_bus 0004:45: busn_res: can not insert [bus 45] under [bus 42-41] (conflicts with (null) [bus 42-41])
> pci 0004:42:06.0: devices behind bridge are unusable because [bus 45] cannot be assigned for them
> pci_bus 0004:46: busn_res: can not insert [bus 46-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
> pci_bus 0004:46: busn_res: [bus 46-41] end is updated to 46
> pci_bus 0004:46: busn_res: can not insert [bus 46] under [bus 42-41] (conflicts with (null) [bus 42-41])
> pci 0004:42:0e.0: devices behind bridge are unusable because [bus 46] cannot be assigned for them
> pci_bus 0004:42: busn_res: [bus 42-41] end is updated to 46
> pci_bus 0004:42: busn_res: can not insert [bus 42-46] under [bus 41] (conflicts with (null) [bus 41])
> pci 0004:41:00.0: devices behind bridge are unusable because [bus 42-46] cannot be assigned for them
> pcieport 0004:40:00.0: bridge has subordinate 41 but max busn 46
> 
> During the initial scan, PCI core doesn't see the switch and since the Root
> Port is not hot plug capable, the secondary bus number gets assigned as the
> subordinate bus number. This means, the PCI core assumes that only one bus
> will appear behind the Root Port since the Root Port is not hot plug
> capable.
> 
> This works perfectly fine for PCIe endpoints connected to the Root Port,
> since they don't extend the bus. However, if a PCIe switch is connected,
> then there is a problem when the downstream busses starts showing up and
> the PCI core doesn't extend the subordinate bus number after initial scan
> during boot.

I suppose this is could also be viewed as a resource management
problem.  

Even in the normal hotplug case, we never know what a hot-added
hierarchy will look like, so we hack around it with the compiled-in
DEFAULT_HOTPLUG_BUS_SIZE and the "hpbussize=" kernel parameter.

It would be nice if we could allocate more bus numbers at hot-add (or
link-up) time as needed.  That's hard after drivers have claimed
nearby devices, but in this case there might not be anything nearby.

> The long term plan is to migrate this driver to the pwrctrl framework,
> once it adds proper support for powering up and enumerating PCIe switches.

"Proper" is hiding some important details here.  pwrctrl already
supports powering up and enumerating switches.  I think this refers to
[1], where Mani says the plan is for pwrctrl to power up everything
before the initial bus scan so we can figure out how many buses are
needed.

Bjorn

[1] https://lore.kernel.org/linux-pci/fle74skju2rorxmfdvosmeyrx3g75rysuszov5ofvde2exj4ir@3kfjyfyhczmn/

Re: [PATCH v2 1/6] Revert "PCI: dw-rockchip: Don't wait for link since we can detect Link Up"

[Niklas Cassel]

Hello Bjorn,

On Fri, Dec 26, 2025 at 04:31:59PM -0600, Bjorn Helgaas wrote:
> > The long term plan is to migrate this driver to the pwrctrl framework,
> > once it adds proper support for powering up and enumerating PCIe switches.
> 
> "Proper" is hiding some important details here.  pwrctrl already
> supports powering up and enumerating switches.  I think this refers to
> [1], where Mani says the plan is for pwrctrl to power up everything
> before the initial bus scan so we can figure out how many buses are
> needed.
> 
> [1] https://lore.kernel.org/linux-pci/fle74skju2rorxmfdvosmeyrx3g75rysuszov5ofvde2exj4ir@3kfjyfyhczmn/

Correct.

This series has already been merged to the pci/controller/dwc branch
(although for some reason this branch is not merged to pci/next yet),
and I can see that Mani have rephrased the commit messages to be more
specific and to avoid the word proper.

Please tell me if there is some futher action needed from my part.


Kind regards,
Niklas