[v2] PCI: brcmstb: Misc small tweaks and fixes

[PATCH v2 5/8] PCI: brcmstb: Fix potential premature regulator disabling

Posted by Jim Quinlan 10 months, 1 week ago

Our system for enabling and disabling regulators is designed to work only
on the port driver below the root complex.  The conditions to discriminate
for this case should be the same when we are adding or removing the bus.
Without this change the regulators may be disabled prematurely when a bus
further down the tree is removed.

Fixes: 9e6be018b263 ("PCI: brcmstb: Enable child bus device regulators from DT")
Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
---
 drivers/pci/controller/pcie-brcmstb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index 56b49d3cae19..e1059e3365bd 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -1440,7 +1440,7 @@ static void brcm_pcie_remove_bus(struct pci_bus *bus)
 	struct subdev_regulators *sr = pcie->sr;
 	struct device *dev = &bus->dev;
 
-	if (!sr)
+	if (!sr || !bus->parent || !pci_is_root_bus(bus->parent))
 		return;
 
 	if (regulator_bulk_disable(sr->num_supplies, sr->supplies))
-- 
2.43.0

Re: [PATCH v2 5/8] PCI: brcmstb: Fix potential premature regulator disabling

Posted by Manivannan Sadhasivam 9 months, 2 weeks ago

On Fri, Feb 14, 2025 at 12:39:33PM -0500, Jim Quinlan wrote:
> Our system for enabling and disabling regulators is designed to work only

'system'? Perhaps 'logic'?

> on the port driver below the root complex.  The conditions to discriminate
> for this case should be the same when we are adding or removing the bus.
> Without this change the regulators may be disabled prematurely when a bus
> further down the tree is removed.
> 
> Fixes: 9e6be018b263 ("PCI: brcmstb: Enable child bus device regulators from DT")
> Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

- Mani

> ---
>  drivers/pci/controller/pcie-brcmstb.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
> index 56b49d3cae19..e1059e3365bd 100644
> --- a/drivers/pci/controller/pcie-brcmstb.c
> +++ b/drivers/pci/controller/pcie-brcmstb.c
> @@ -1440,7 +1440,7 @@ static void brcm_pcie_remove_bus(struct pci_bus *bus)
>  	struct subdev_regulators *sr = pcie->sr;
>  	struct device *dev = &bus->dev;
>  
> -	if (!sr)
> +	if (!sr || !bus->parent || !pci_is_root_bus(bus->parent))
>  		return;
>  
>  	if (regulator_bulk_disable(sr->num_supplies, sr->supplies))
> -- 
> 2.43.0
> 

-- 
மணிவண்ணன் சதாசிவம்

Re: [PATCH v2 5/8] PCI: brcmstb: Fix potential premature regulator disabling

Posted by Florian Fainelli 10 months ago


On 2/14/2025 9:39 AM, Jim Quinlan wrote:
> Our system for enabling and disabling regulators is designed to work only
> on the port driver below the root complex.  The conditions to discriminate
> for this case should be the same when we are adding or removing the bus.
> Without this change the regulators may be disabled prematurely when a bus
> further down the tree is removed.
> 
> Fixes: 9e6be018b263 ("PCI: brcmstb: Enable child bus device regulators from DT")
> Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>

Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
-- 
Florian