[v3] PCI: apple: Add support for t6020

[PATCH v3 01/13] PCI: apple: Set only available ports up

Posted by Marc Zyngier 1 month, 1 week ago

From: Janne Grunau <j@jannau.net>

Iterating over disabled ports results in of_irq_parse_raw() parsing
the wrong "interrupt-map" entries, as it takes the status of the node
into account.

This became apparent after disabling unused PCIe ports in the Apple
Silicon device trees instead of deleting them.

Switching from for_each_child_of_node() to for_each_available_child_of_node()
solves this issue.

Link: https://lore.kernel.org/asahi/20230214-apple_dts_pcie_disable_unused-v1-0-5ea0d3ddcde3@jannau.net/
Link: https://lore.kernel.org/asahi/1ea2107a-bb86-8c22-0bbc-82c453ab08ce@linaro.org/
Fixes: 1e33888fbe44 ("PCI: apple: Add initial hardware bring-up")
Fixes: a0189fdfb73d ("arm64: dts: apple: t8103: Disable unused PCIe ports")
Cc: stable@vger.kernel.org
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Tested-by: Janne Grunau <j@jannau.net>
Signed-off-by: Janne Grunau <j@jannau.net>
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/pci/controller/pcie-apple.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/controller/pcie-apple.c b/drivers/pci/controller/pcie-apple.c
index a7e51bc1c2fe8..842f8cee7c868 100644
--- a/drivers/pci/controller/pcie-apple.c
+++ b/drivers/pci/controller/pcie-apple.c
@@ -755,7 +755,7 @@ static int apple_pcie_init(struct pci_config_window *cfg)
 	if (ret)
 		return ret;
 
-	for_each_child_of_node(dev->of_node, of_port) {
+	for_each_available_child_of_node(dev->of_node, of_port) {
 		ret = apple_pcie_setup_port(pcie, of_port);
 		if (ret) {
 			dev_err(pcie->dev, "Port %pOF setup fail: %d\n", of_port, ret);
-- 
2.39.2

Re: [PATCH v3 01/13] PCI: apple: Set only available ports up

Posted by Manivannan Sadhasivam 3 weeks, 6 days ago

On Tue, Apr 01, 2025 at 10:17:01AM +0100, Marc Zyngier wrote:
> From: Janne Grunau <j@jannau.net>
> 
> Iterating over disabled ports results in of_irq_parse_raw() parsing
> the wrong "interrupt-map" entries, as it takes the status of the node

'as it doesn't take account'?

> into account.
> 
> This became apparent after disabling unused PCIe ports in the Apple
> Silicon device trees instead of deleting them.
> 
> Switching from for_each_child_of_node() to for_each_available_child_of_node()
> solves this issue.
> 
> Link: https://lore.kernel.org/asahi/20230214-apple_dts_pcie_disable_unused-v1-0-5ea0d3ddcde3@jannau.net/
> Link: https://lore.kernel.org/asahi/1ea2107a-bb86-8c22-0bbc-82c453ab08ce@linaro.org/
> Fixes: 1e33888fbe44 ("PCI: apple: Add initial hardware bring-up")
> Fixes: a0189fdfb73d ("arm64: dts: apple: t8103: Disable unused PCIe ports")
> Cc: stable@vger.kernel.org
> Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
> Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
> Tested-by: Janne Grunau <j@jannau.net>
> Signed-off-by: Janne Grunau <j@jannau.net>
> Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
> Signed-off-by: Marc Zyngier <maz@kernel.org>

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

- Mani

> ---
>  drivers/pci/controller/pcie-apple.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/pcie-apple.c b/drivers/pci/controller/pcie-apple.c
> index a7e51bc1c2fe8..842f8cee7c868 100644
> --- a/drivers/pci/controller/pcie-apple.c
> +++ b/drivers/pci/controller/pcie-apple.c
> @@ -755,7 +755,7 @@ static int apple_pcie_init(struct pci_config_window *cfg)
>  	if (ret)
>  		return ret;
>  
> -	for_each_child_of_node(dev->of_node, of_port) {
> +	for_each_available_child_of_node(dev->of_node, of_port) {
>  		ret = apple_pcie_setup_port(pcie, of_port);
>  		if (ret) {
>  			dev_err(pcie->dev, "Port %pOF setup fail: %d\n", of_port, ret);
> -- 
> 2.39.2
> 

-- 
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Re: [PATCH v3 01/13] PCI: apple: Set only available ports up

Posted by Marc Zyngier 3 weeks, 6 days ago

On Sun, 13 Apr 2025 17:57:35 +0100,
Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> wrote:
> 
> On Tue, Apr 01, 2025 at 10:17:01AM +0100, Marc Zyngier wrote:
> > From: Janne Grunau <j@jannau.net>
> > 
> > Iterating over disabled ports results in of_irq_parse_raw() parsing
> > the wrong "interrupt-map" entries, as it takes the status of the node
> 
> 'as it doesn't take account'?
> 
> > into account.

No, I really mean it in the positive form. of_irq_parse_raw() checks
of_device_is_available(), and gets really confused if walking from a
disabled port. You end up with the interrupt for the next *available*
port, and everything goes pear shaped from then onwards.

So IMO "as it takes into account" describes pretty accurately the
situation.

	M.

-- 
Jazz isn't dead. It just smells funny.

Re: [PATCH v3 01/13] PCI: apple: Set only available ports up

Posted by Manivannan Sadhasivam 3 weeks, 5 days ago

On Sun, Apr 13, 2025 at 09:00:23PM +0100, Marc Zyngier wrote:
> On Sun, 13 Apr 2025 17:57:35 +0100,
> Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> wrote:
> > 
> > On Tue, Apr 01, 2025 at 10:17:01AM +0100, Marc Zyngier wrote:
> > > From: Janne Grunau <j@jannau.net>
> > > 
> > > Iterating over disabled ports results in of_irq_parse_raw() parsing
> > > the wrong "interrupt-map" entries, as it takes the status of the node
> > 
> > 'as it doesn't take account'?
> > 
> > > into account.
> 
> No, I really mean it in the positive form. of_irq_parse_raw() checks
> of_device_is_available(), and gets really confused if walking from a
> disabled port. You end up with the interrupt for the next *available*
> port, and everything goes pear shaped from then onwards.
> 

Ah okay. 

> So IMO "as it takes into account" describes pretty accurately the
> situation.
> 

Thanks for the clarification.

- Mani

-- 
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