linux-kernel - RE: [PATCH V2 2/4] dt-bindings: imx6q-pcie: Add wake-gpios property

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID:
 <DB9PR04MB8429588E7CF00BDC9CDA863F92AA2@DB9PR04MB8429.eurprd04.prod.outlook.com>
Date: Mon, 7 Apr 2025 07:18:32 +0000
From: Sherry Sun <sherry.sun@....com>
To: Francesco Dolcini <francesco@...cini.it>
CC: Hongxing Zhu <hongxing.zhu@....com>, "l.stach@...gutronix.de"
	<l.stach@...gutronix.de>, "lpieralisi@...nel.org" <lpieralisi@...nel.org>,
	"kw@...ux.com" <kw@...ux.com>, "robh@...nel.org" <robh@...nel.org>,
	"bhelgaas@...gle.com" <bhelgaas@...gle.com>,
	"krzysztof.kozlowski+dt@...aro.org" <krzysztof.kozlowski+dt@...aro.org>,
	"conor+dt@...nel.org" <conor+dt@...nel.org>, "shawnguo@...nel.org"
	<shawnguo@...nel.org>, "s.hauer@...gutronix.de" <s.hauer@...gutronix.de>,
	"kernel@...gutronix.de" <kernel@...gutronix.de>, "festevam@...il.com"
	<festevam@...il.com>, dl-linux-imx <linux-imx@....com>,
	"linux-pci@...r.kernel.org" <linux-pci@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org"
	<linux-arm-kernel@...ts.infradead.org>, "devicetree@...r.kernel.org"
	<devicetree@...r.kernel.org>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>
Subject: RE: [PATCH V2 2/4] dt-bindings: imx6q-pcie: Add wake-gpios property



> -----Original Message-----
> From: Francesco Dolcini <francesco@...cini.it>
> Sent: Friday, April 4, 2025 5:42 PM
> To: Sherry Sun <sherry.sun@....com>
> Cc: Hongxing Zhu <hongxing.zhu@....com>; l.stach@...gutronix.de;
> lpieralisi@...nel.org; kw@...ux.com; robh@...nel.org;
> bhelgaas@...gle.com; krzysztof.kozlowski+dt@...aro.org;
> conor+dt@...nel.org; shawnguo@...nel.org; s.hauer@...gutronix.de;
> kernel@...gutronix.de; festevam@...il.com; dl-linux-imx <linux-
> imx@....com>; linux-pci@...r.kernel.org; linux-arm-
> kernel@...ts.infradead.org; devicetree@...r.kernel.org; linux-
> kernel@...r.kernel.org
> Subject: Re: [PATCH V2 2/4] dt-bindings: imx6q-pcie: Add wake-gpios property
> 
> Hello
> 
> On Wed, Dec 13, 2023 at 05:28:48PM +0800, Sherry Sun wrote:
> > Add wake-gpios property that can be used to wakeup the host processor.
> >
> > Signed-off-by: Sherry Sun <sherry.sun@....com>
> > Reviewed-by: Richard Zhu <hongxing.zhu@....com>
> > ---
> >  Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.yaml | 6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.yaml
> > b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.yaml
> > index 81bbb8728f0f..fba757d937e1 100644
> > --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.yaml
> > +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.yaml
> > @@ -72,6 +72,12 @@ properties:
> >        L=operation state) (optional required).
> >      type: boolean
> >
> > +  wake-gpios:
> > +    description: If present this property specifies WAKE# sideband signaling
> > +      to implement wakeup functionality. This is an input GPIO pin for the
> Root
> > +      Port mode here. Host drivers will wakeup the host using the IRQ
> > +      corresponding to the passed GPIO.
> > +
> 
> From what I know it is possible to share the same WAKE# signal for multiple
> root ports. Is this going to work fine with this binding? Same question on the
> driver.
> 
> We do have design exactly like that, so it's not a theoretical question.
> 

Hi Francesco,
The current design doesn't support such case, maybe some changes in the driver could achieve that (mark the wake-gpio as GPIOD_FLAGS_BIT_NONEXCLUSIVE and the interrupt as IRQF_SHARED, etc.).
But usually each RC has its own WAKE# pin assigned. We have not come across a case where multiple RC share the same WAKE# pin.

Best Regards
Sherry