linux-kernel - Re: [PATCH v8 13/17] PCI/pwrctl: reuse the OF node for power controlled devices

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Message-ID: <20240611225603.GA1005810@bhelgaas>
Date: Tue, 11 Jun 2024 17:56:03 -0500
From: Bjorn Helgaas <helgaas@...nel.org>
To: Bartosz Golaszewski <brgl@...ev.pl>
Cc: Liam Girdwood <lgirdwood@...il.com>, Mark Brown <broonie@...nel.org>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Marcel Holtmann <marcel@...tmann.org>,
	Luiz Augusto von Dentz <luiz.dentz@...il.com>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	Balakrishna Godavarthi <quic_bgodavar@...cinc.com>,
	Rocky Liao <quic_rjliao@...cinc.com>, Kalle Valo <kvalo@...nel.org>,
	Jeff Johnson <jjohnson@...nel.org>,
	Bjorn Andersson <andersson@...nel.org>,
	Konrad Dybcio <konrad.dybcio@...aro.org>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Srini Kandagatla <srinivas.kandagatla@...aro.org>,
	Elliot Berman <quic_eberman@...cinc.com>,
	Caleb Connolly <caleb.connolly@...aro.org>,
	Neil Armstrong <neil.armstrong@...aro.org>,
	Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
	Alex Elder <elder@...nel.org>, linux-arm-msm@...r.kernel.org,
	linux-kernel@...r.kernel.org, devicetree@...r.kernel.org,
	linux-bluetooth@...r.kernel.org, netdev@...r.kernel.org,
	linux-wireless@...r.kernel.org, ath11k@...ts.infradead.org,
	Jeff Johnson <quic_jjohnson@...cinc.com>,
	ath12k@...ts.infradead.org, linux-pm@...r.kernel.org,
	linux-pci@...r.kernel.org,
	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>,
	kernel@...cinc.com, Amit Pundir <amit.pundir@...aro.org>
Subject: Re: [PATCH v8 13/17] PCI/pwrctl: reuse the OF node for power
 controlled devices

On Tue, May 28, 2024 at 09:03:21PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
> 
> With PCI power control we deal with two struct device objects bound to
> two different drivers but consuming the same OF node. We must not bind
> the pinctrl twice. To that end: before setting the OF node of the newly
> instantiated PCI device, check if a platform device consuming the same
> OF node doesn't already exist on the platform bus and - if so - mark the
> PCI device as reusing the OF node.
> 
> Tested-by: Amit Pundir <amit.pundir@...aro.org>
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>

With s/reuse/Reuse/ in subject to match history,

Acked-by: Bjorn Helgaas <bhelgaas@...gle.com>

Would be good to get Rob's ack as well.

> ---
>  drivers/pci/of.c | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/of.c b/drivers/pci/of.c
> index 51e3dd0ea5ab..b908fe1ae951 100644
> --- a/drivers/pci/of.c
> +++ b/drivers/pci/of.c
> @@ -6,6 +6,7 @@
>   */
>  #define pr_fmt(fmt)	"PCI: OF: " fmt
>  
> +#include <linux/cleanup.h>
>  #include <linux/irqdomain.h>
>  #include <linux/kernel.h>
>  #include <linux/pci.h>
> @@ -13,6 +14,7 @@
>  #include <linux/of_irq.h>
>  #include <linux/of_address.h>
>  #include <linux/of_pci.h>
> +#include <linux/platform_device.h>
>  #include "pci.h"
>  
>  #ifdef CONFIG_PCI
> @@ -25,16 +27,20 @@
>   */
>  int pci_set_of_node(struct pci_dev *dev)
>  {
> -	struct device_node *node;
> -
>  	if (!dev->bus->dev.of_node)
>  		return 0;
>  
> -	node = of_pci_find_child_device(dev->bus->dev.of_node, dev->devfn);
> +	struct device_node *node __free(device_node) =
> +		of_pci_find_child_device(dev->bus->dev.of_node, dev->devfn);
>  	if (!node)
>  		return 0;
>  
> -	device_set_node(&dev->dev, of_fwnode_handle(node));
> +	struct device *pdev __free(put_device) =
> +		bus_find_device_by_of_node(&platform_bus_type, node);
> +	if (pdev)
> +		dev->bus->dev.of_node_reused = true;
> +
> +	device_set_node(&dev->dev, of_fwnode_handle(no_free_ptr(node)));
>  	return 0;
>  }
>  
> 
> -- 
> 2.43.0
>