[PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Kiran Gunda]

The peripheral ownership check is not necessary on single master
platforms. Hence, enforce the peripheral ownership check optionally.

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Tested-by: Shawn Guo <shawnguo@kernel.org>
---
v2:
	Fixed the commit message.
	Added Shawn's 'Tested-by' tag.

v1:
	This patch depends on the below patch series. Please take this patch
	along with this series.

	[PATCH V2 00/12]: spmi: pmic-arb: Support for HW v5 and other fixes

 Documentation/devicetree/bindings/spmi/qcom,spmi-pmic-arb.txt | 6 ++++++
 drivers/spmi/spmi-pmic-arb.c                                  | 7 ++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/spmi/qcom,spmi-pmic-arb.txt b/Documentation/devicetree/bindings/spmi/qcom,spmi-pmic-arb.txt
index e16b9b5..da708e8 100644
--- a/Documentation/devicetree/bindings/spmi/qcom,spmi-pmic-arb.txt
+++ b/Documentation/devicetree/bindings/spmi/qcom,spmi-pmic-arb.txt
@@ -42,6 +42,10 @@ Required properties:
     cell 4: interrupt flags indicating level-sense information, as defined in
             dt-bindings/interrupt-controller/irq.h
 
+Optional properties:
+- qcom,enforce-ownership : A boolean property. If defined the peripheral
+			   ownership check is enforced. Otherwise the ownership
+			   check is ignored.
 Example:
 
 	spmi {
@@ -62,4 +66,6 @@ Example:
 
 		interrupt-controller;
 		#interrupt-cells = <4>;
+
+		qcom,enforce-ownership;
 	};
diff --git a/drivers/spmi/spmi-pmic-arb.c b/drivers/spmi/spmi-pmic-arb.c
index ca9bdd3..354c949 100644
--- a/drivers/spmi/spmi-pmic-arb.c
+++ b/drivers/spmi/spmi-pmic-arb.c
@@ -167,6 +167,7 @@ struct spmi_pmic_arb {
 	u16			*ppid_to_apid;
 	u16			last_apid;
 	struct apid_data	apid_data[PMIC_ARB_MAX_PERIPHS];
+	bool			enforce_ownership;
 };
 
 /**
@@ -707,7 +708,8 @@ static int qpnpint_irq_domain_dt_translate(struct irq_domain *d,
 	}
 
 	apid = rc;
-	if (pmic_arb->apid_data[apid].irq_ee != pmic_arb->ee) {
+	if (pmic_arb->enforce_ownership &&
+			pmic_arb->apid_data[apid].irq_ee != pmic_arb->ee) {
 		dev_err(&pmic_arb->spmic->dev, "failed to xlate sid = %#x, periph = %#x, irq = %u: ee=%u but owner=%u\n",
 			intspec[0], intspec[1], intspec[2], pmic_arb->ee,
 			pmic_arb->apid_data[apid].irq_ee);
@@ -1236,6 +1238,9 @@ static int spmi_pmic_arb_probe(struct platform_device *pdev)
 	}
 
 	pmic_arb->ee = ee;
+	pmic_arb->enforce_ownership =
+	    of_property_read_bool(pdev->dev.of_node, "qcom,enforce-ownership");
+
 	mapping_table = devm_kcalloc(&ctrl->dev, PMIC_ARB_MAX_PERIPHS,
 					sizeof(*mapping_table), GFP_KERNEL);
 	if (!mapping_table) {
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Stephen Boyd]

On 08/18/2017 08:28 AM, Kiran Gunda wrote:
> The peripheral ownership check is not necessary on single master
> platforms. Hence, enforce the peripheral ownership check optionally.
>
> Signed-off-by: Kiran Gunda <kgunda-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
> Tested-by: Shawn Guo <shawnguo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> ---

This sounds like a band-aid. Isn't the gpio driver going to keep probing
all the pins that are not supposed to be accessed due to security
constraints? What exactly is failing in the gpio case?

Also, I thought we were getting rid of the ownership checks? Or at
least, putting them behind some debug kernel feature check or something?

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Stephen Boyd]

On 08/18/2017 08:28 AM, Kiran Gunda wrote:
> The peripheral ownership check is not necessary on single master
> platforms. Hence, enforce the peripheral ownership check optionally.
>
> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
> Tested-by: Shawn Guo <shawnguo@kernel.org>
> ---

This sounds like a band-aid. Isn't the gpio driver going to keep probing
all the pins that are not supposed to be accessed due to security
constraints? What exactly is failing in the gpio case?

Also, I thought we were getting rid of the ownership checks? Or at
least, putting them behind some debug kernel feature check or something?

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Shawn Guo]

On Mon, Aug 21, 2017 at 04:18:58PM -0700, Stephen Boyd wrote:
> On 08/18/2017 08:28 AM, Kiran Gunda wrote:
> > The peripheral ownership check is not necessary on single master
> > platforms. Hence, enforce the peripheral ownership check optionally.
> >
> > Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
> > Tested-by: Shawn Guo <shawnguo@kernel.org>
> > ---
> 
> This sounds like a band-aid. Isn't the gpio driver going to keep probing
> all the pins that are not supposed to be accessed due to security
> constraints? What exactly is failing in the gpio case?

There is a platform_irq_count() call in pinctrl-spmi-gpio probe
function.  Due to the owner check in spmi-pmic-arb IRQ domain
qpnpint_irq_domain_dt_translate() function, the call will return irq
number as zero and cause pmic_gpio_probe() fail with -EINVAL error.

[    1.608516] [<ffff00000860e51c>] qpnpint_irq_domain_dt_translate+0x168/0x194
[    1.613557] [<ffff000008117040>] irq_create_fwspec_mapping+0x17c/0x2d8
[    1.620672] [<ffff000008117200>] irq_create_of_mapping+0x64/0x74
[    1.627008] [<ffff0000087b4fac>] of_irq_get+0x54/0x64
[    1.633169] [<ffff00000856b824>] platform_get_irq+0x20/0x150
[    1.638117] [<ffff00000856b97c>] platform_irq_count+0x28/0x44
[    1.643850] [<ffff0000083cf12c>] pmic_gpio_probe+0x50/0x544

Shawn

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Shawn Guo]

On Mon, Aug 21, 2017 at 04:18:58PM -0700, Stephen Boyd wrote:
> On 08/18/2017 08:28 AM, Kiran Gunda wrote:
> > The peripheral ownership check is not necessary on single master
> > platforms. Hence, enforce the peripheral ownership check optionally.
> >
> > Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
> > Tested-by: Shawn Guo <shawnguo@kernel.org>
> > ---
> 
> This sounds like a band-aid. Isn't the gpio driver going to keep probing
> all the pins that are not supposed to be accessed due to security
> constraints? What exactly is failing in the gpio case?
> 
> Also, I thought we were getting rid of the ownership checks? Or at
> least, putting them behind some debug kernel feature check or something?

I'm wondering that too.  Since we have the following patch to remove the
check on read/write access anyway, why are we adding the check in .xlate
hook?

spmi: pmic-arb: remove the read/write access checks

Shawn

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Stephen Boyd]

On 08/22, Shawn Guo wrote:
> On Mon, Aug 21, 2017 at 04:18:58PM -0700, Stephen Boyd wrote:
> > On 08/18/2017 08:28 AM, Kiran Gunda wrote:
> > > The peripheral ownership check is not necessary on single master
> > > platforms. Hence, enforce the peripheral ownership check optionally.
> > >
> > > Signed-off-by: Kiran Gunda <kgunda-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
> > > Tested-by: Shawn Guo <shawnguo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> > > ---
> > 
> > This sounds like a band-aid. Isn't the gpio driver going to keep probing
> > all the pins that are not supposed to be accessed due to security
> > constraints? What exactly is failing in the gpio case?
> 
> There is a platform_irq_count() call in pinctrl-spmi-gpio probe
> function.  Due to the owner check in spmi-pmic-arb IRQ domain
> qpnpint_irq_domain_dt_translate() function, the call will return irq
> number as zero and cause pmic_gpio_probe() fail with -EINVAL error.
> 
> [    1.608516] [<ffff00000860e51c>] qpnpint_irq_domain_dt_translate+0x168/0x194
> [    1.613557] [<ffff000008117040>] irq_create_fwspec_mapping+0x17c/0x2d8
> [    1.620672] [<ffff000008117200>] irq_create_of_mapping+0x64/0x74
> [    1.627008] [<ffff0000087b4fac>] of_irq_get+0x54/0x64
> [    1.633169] [<ffff00000856b824>] platform_get_irq+0x20/0x150
> [    1.638117] [<ffff00000856b97c>] platform_irq_count+0x28/0x44
> [    1.643850] [<ffff0000083cf12c>] pmic_gpio_probe+0x50/0x544
> 

Hmm. Ok. I guess platform_irq_count() has to go and create irq
mappings if they haven't been created yet and that then causes us
to check if we can even get the interrupt for this particular
irq? There are some interrupt lines that are not routed to the
application processor in the system, so the irq_ee (irq execution
environment) is different. This check is there to avoid creating
flow handlers for irqs that can't be triggered.

I can see how trying to request that irq doesn't make sense,
because it won't ever happen. But preventing that from being
translated is confusing. Perhaps we can move the check for irq_ee
to the irq_request_resources() callback in the irqchip? That way,
we can fail installing the flow handler for the interrupt we
can't ever receive, but otherwise translate the interrupt number
so we can keep counting them.

Also, I see that on v4.13-rc series the read/write checks are
causing the led driver to fail in a different way:

    spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc040
    qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x40 failed
    leds-gpio soc:leds: Error applying setting, reverse things back
    spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc041
    qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x41 failed
    leds-gpio: probe of soc:leds failed with error -1 

Are you seeing similar behavior?

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Stephen Boyd]

On 08/22, Shawn Guo wrote:
> On Mon, Aug 21, 2017 at 04:18:58PM -0700, Stephen Boyd wrote:
> > On 08/18/2017 08:28 AM, Kiran Gunda wrote:
> > > The peripheral ownership check is not necessary on single master
> > > platforms. Hence, enforce the peripheral ownership check optionally.
> > >
> > > Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
> > > Tested-by: Shawn Guo <shawnguo@kernel.org>
> > > ---
> > 
> > This sounds like a band-aid. Isn't the gpio driver going to keep probing
> > all the pins that are not supposed to be accessed due to security
> > constraints? What exactly is failing in the gpio case?
> 
> There is a platform_irq_count() call in pinctrl-spmi-gpio probe
> function.  Due to the owner check in spmi-pmic-arb IRQ domain
> qpnpint_irq_domain_dt_translate() function, the call will return irq
> number as zero and cause pmic_gpio_probe() fail with -EINVAL error.
> 
> [    1.608516] [<ffff00000860e51c>] qpnpint_irq_domain_dt_translate+0x168/0x194
> [    1.613557] [<ffff000008117040>] irq_create_fwspec_mapping+0x17c/0x2d8
> [    1.620672] [<ffff000008117200>] irq_create_of_mapping+0x64/0x74
> [    1.627008] [<ffff0000087b4fac>] of_irq_get+0x54/0x64
> [    1.633169] [<ffff00000856b824>] platform_get_irq+0x20/0x150
> [    1.638117] [<ffff00000856b97c>] platform_irq_count+0x28/0x44
> [    1.643850] [<ffff0000083cf12c>] pmic_gpio_probe+0x50/0x544
> 

Hmm. Ok. I guess platform_irq_count() has to go and create irq
mappings if they haven't been created yet and that then causes us
to check if we can even get the interrupt for this particular
irq? There are some interrupt lines that are not routed to the
application processor in the system, so the irq_ee (irq execution
environment) is different. This check is there to avoid creating
flow handlers for irqs that can't be triggered.

I can see how trying to request that irq doesn't make sense,
because it won't ever happen. But preventing that from being
translated is confusing. Perhaps we can move the check for irq_ee
to the irq_request_resources() callback in the irqchip? That way,
we can fail installing the flow handler for the interrupt we
can't ever receive, but otherwise translate the interrupt number
so we can keep counting them.

Also, I see that on v4.13-rc series the read/write checks are
causing the led driver to fail in a different way:

    spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc040
    qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x40 failed
    leds-gpio soc:leds: Error applying setting, reverse things back
    spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc041
    qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x41 failed
    leds-gpio: probe of soc:leds failed with error -1 

Are you seeing similar behavior?

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[kgunda]

On 2017-08-23 02:01, Stephen Boyd wrote:
> On 08/22, Shawn Guo wrote:
>> On Mon, Aug 21, 2017 at 04:18:58PM -0700, Stephen Boyd wrote:
>> > On 08/18/2017 08:28 AM, Kiran Gunda wrote:
>> > > The peripheral ownership check is not necessary on single master
>> > > platforms. Hence, enforce the peripheral ownership check optionally.
>> > >
>> > > Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
>> > > Tested-by: Shawn Guo <shawnguo@kernel.org>
>> > > ---
>> >
>> > This sounds like a band-aid. Isn't the gpio driver going to keep probing
>> > all the pins that are not supposed to be accessed due to security
>> > constraints? What exactly is failing in the gpio case?
>> 
>> There is a platform_irq_count() call in pinctrl-spmi-gpio probe
>> function.  Due to the owner check in spmi-pmic-arb IRQ domain
>> qpnpint_irq_domain_dt_translate() function, the call will return irq
>> number as zero and cause pmic_gpio_probe() fail with -EINVAL error.
>> 
>> [    1.608516] [<ffff00000860e51c>] 
>> qpnpint_irq_domain_dt_translate+0x168/0x194
>> [    1.613557] [<ffff000008117040>] 
>> irq_create_fwspec_mapping+0x17c/0x2d8
>> [    1.620672] [<ffff000008117200>] irq_create_of_mapping+0x64/0x74
>> [    1.627008] [<ffff0000087b4fac>] of_irq_get+0x54/0x64
>> [    1.633169] [<ffff00000856b824>] platform_get_irq+0x20/0x150
>> [    1.638117] [<ffff00000856b97c>] platform_irq_count+0x28/0x44
>> [    1.643850] [<ffff0000083cf12c>] pmic_gpio_probe+0x50/0x544
>> 
> 
> Hmm. Ok. I guess platform_irq_count() has to go and create irq
> mappings if they haven't been created yet and that then causes us
> to check if we can even get the interrupt for this particular
> irq? There are some interrupt lines that are not routed to the
> application processor in the system, so the irq_ee (irq execution
> environment) is different. This check is there to avoid creating
> flow handlers for irqs that can't be triggered.
> 
> I can see how trying to request that irq doesn't make sense,
> because it won't ever happen. But preventing that from being
> translated is confusing. Perhaps we can move the check for irq_ee
> to the irq_request_resources() callback in the irqchip? That way,
> we can fail installing the flow handler for the interrupt we
> can't ever receive, but otherwise translate the interrupt number
> so we can keep counting them.
> 
Hi Stephen,
The idea to move the ownership check to irq_request_resources sounds 
good.
I am dropping this patch and sent the new patch to move the irq 
ownership to
irq_request_resource. Following is the patchwork link.

Shawn, can you please give a try with it?
https://patchwork.kernel.org/patch/9917315/

> Also, I see that on v4.13-rc series the read/write checks are
> causing the led driver to fail in a different way:
> 
>     spmi spmi-0: error: impermissible write to peripheral sid:0 
> addr:0xc040
>     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x40 failed
>     leds-gpio soc:leds: Error applying setting, reverse things back
>     spmi spmi-0: error: impermissible write to peripheral sid:0 
> addr:0xc041
>     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x41 failed
>     leds-gpio: probe of soc:leds failed with error -1
> 
> Are you seeing similar behavior?
With the new patch series these errors will go away, as we are removing 
the ownership
checks from the read/write path.

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Shawn Guo]

On Tue, Aug 22, 2017 at 01:31:32PM -0700, Stephen Boyd wrote:
> Also, I see that on v4.13-rc series the read/write checks are
> causing the led driver to fail in a different way:
> 
>     spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc040
>     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x40 failed
>     leds-gpio soc:leds: Error applying setting, reverse things back
>     spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc041
>     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x41 failed
>     leds-gpio: probe of soc:leds failed with error -1 
> 
> Are you seeing similar behavior?

Yes.  I forgot to mention that, and leds-gpio failure is gone after
applying Kiran's patch below.

spmi: pmic-arb: remove the read/write access checks

Shawn

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Stephen Boyd]

On 08/24, Shawn Guo wrote:
> On Tue, Aug 22, 2017 at 01:31:32PM -0700, Stephen Boyd wrote:
> > Also, I see that on v4.13-rc series the read/write checks are
> > causing the led driver to fail in a different way:
> > 
> >     spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc040
> >     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x40 failed
> >     leds-gpio soc:leds: Error applying setting, reverse things back
> >     spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc041
> >     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x41 failed
> >     leds-gpio: probe of soc:leds failed with error -1 
> > 
> > Are you seeing similar behavior?
> 
> Yes.  I forgot to mention that, and leds-gpio failure is gone after
> applying Kiran's patch below.
> 
> spmi: pmic-arb: remove the read/write access checks
> 

Sure. Removing the checks will silence the warnings, but it still
means that we're attempting to configure GPIOs that we shouldn't
be configuring. Is there some sort of default configuration that
gets applied to all pins by default?

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Stephen Boyd]

On 08/24, Shawn Guo wrote:
> On Tue, Aug 22, 2017 at 01:31:32PM -0700, Stephen Boyd wrote:
> > Also, I see that on v4.13-rc series the read/write checks are
> > causing the led driver to fail in a different way:
> > 
> >     spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc040
> >     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x40 failed
> >     leds-gpio soc:leds: Error applying setting, reverse things back
> >     spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc041
> >     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x41 failed
> >     leds-gpio: probe of soc:leds failed with error -1 
> > 
> > Are you seeing similar behavior?
> 
> Yes.  I forgot to mention that, and leds-gpio failure is gone after
> applying Kiran's patch below.
> 
> spmi: pmic-arb: remove the read/write access checks
> 

Sure. Removing the checks will silence the warnings, but it still
means that we're attempting to configure GPIOs that we shouldn't
be configuring. Is there some sort of default configuration that
gets applied to all pins by default?

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Shawn Guo]

On Thu, Aug 24, 2017 at 11:37:01AM -0700, Stephen Boyd wrote:
> On 08/24, Shawn Guo wrote:
> > On Tue, Aug 22, 2017 at 01:31:32PM -0700, Stephen Boyd wrote:
> > > Also, I see that on v4.13-rc series the read/write checks are
> > > causing the led driver to fail in a different way:
> > > 
> > >     spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc040
> > >     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x40 failed
> > >     leds-gpio soc:leds: Error applying setting, reverse things back
> > >     spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc041
> > >     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x41 failed
> > >     leds-gpio: probe of soc:leds failed with error -1 
> > > 
> > > Are you seeing similar behavior?
> > 
> > Yes.  I forgot to mention that, and leds-gpio failure is gone after
> > applying Kiran's patch below.
> > 
> > spmi: pmic-arb: remove the read/write access checks
> > 
> 
> Sure. Removing the checks will silence the warnings, but it still
> means that we're attempting to configure GPIOs that we shouldn't
> be configuring.

The driver is attempting to configure the GPIOs that device tree tells
to.

	led@3 {                        
		label = "apq8016-sbc:green:user3";
		gpios = <&pm8916_gpios 1 GPIO_ACTIVE_HIGH>;
		linux,default-trigger = "mmc1";
		default-state = "off";         
	};

Are you saying, in case of user3 led above, device tree shouldn't use
GPIO <&pm8916_gpios 1> there at all?

> Is there some sort of default configuration that
> gets applied to all pins by default?

I do not quite understand what you are asking and how that is related to
the thing we discuss here.  But my understanding is that spmi_arb
read/write access is used not only by pinctrl API to set up pinmux for
GPIO function, but also by GPIO API to actually drive the GPIO.

Shawn

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Stephen Boyd]

On 08/25, Shawn Guo wrote:
> On Thu, Aug 24, 2017 at 11:37:01AM -0700, Stephen Boyd wrote:
> > On 08/24, Shawn Guo wrote:
> > > On Tue, Aug 22, 2017 at 01:31:32PM -0700, Stephen Boyd wrote:
> > > > Also, I see that on v4.13-rc series the read/write checks are
> > > > causing the led driver to fail in a different way:
> > > > 
> > > >     spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc040
> > > >     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x40 failed
> > > >     leds-gpio soc:leds: Error applying setting, reverse things back
> > > >     spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc041
> > > >     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x41 failed
> > > >     leds-gpio: probe of soc:leds failed with error -1 
> > > > 
> > > > Are you seeing similar behavior?
> > > 
> > > Yes.  I forgot to mention that, and leds-gpio failure is gone after
> > > applying Kiran's patch below.
> > > 
> > > spmi: pmic-arb: remove the read/write access checks
> > > 
> > 
> > Sure. Removing the checks will silence the warnings, but it still
> > means that we're attempting to configure GPIOs that we shouldn't
> > be configuring.
> 
> The driver is attempting to configure the GPIOs that device tree tells
> to.
> 
> 	led@3 {                        
> 		label = "apq8016-sbc:green:user3";
> 		gpios = <&pm8916_gpios 1 GPIO_ACTIVE_HIGH>;
> 		linux,default-trigger = "mmc1";
> 		default-state = "off";         
> 	};
> 
> Are you saying, in case of user3 led above, device tree shouldn't use
> GPIO <&pm8916_gpios 1> there at all?

Right. Does the GPIO work? If so, it sounds like the read/write
access checks in spmi pmic arb don't work properly.

> 
> > Is there some sort of default configuration that
> > gets applied to all pins by default?
> 
> I do not quite understand what you are asking and how that is related to
> the thing we discuss here.  But my understanding is that spmi_arb
> read/write access is used not only by pinctrl API to set up pinmux for
> GPIO function, but also by GPIO API to actually drive the GPIO.
> 

Ah I got confused because I thought we numbered GPIO pins from 0,
but on the PMIC we number from 1. I see that base = -1 assignment
now. I thought that all pins on the pmic were being configured
somewhere because I didn't see a gpio 0 usage in DT.

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Stephen Boyd]

On 08/25, Shawn Guo wrote:
> On Thu, Aug 24, 2017 at 11:37:01AM -0700, Stephen Boyd wrote:
> > On 08/24, Shawn Guo wrote:
> > > On Tue, Aug 22, 2017 at 01:31:32PM -0700, Stephen Boyd wrote:
> > > > Also, I see that on v4.13-rc series the read/write checks are
> > > > causing the led driver to fail in a different way:
> > > > 
> > > >     spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc040
> > > >     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x40 failed
> > > >     leds-gpio soc:leds: Error applying setting, reverse things back
> > > >     spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc041
> > > >     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x41 failed
> > > >     leds-gpio: probe of soc:leds failed with error -1 
> > > > 
> > > > Are you seeing similar behavior?
> > > 
> > > Yes.  I forgot to mention that, and leds-gpio failure is gone after
> > > applying Kiran's patch below.
> > > 
> > > spmi: pmic-arb: remove the read/write access checks
> > > 
> > 
> > Sure. Removing the checks will silence the warnings, but it still
> > means that we're attempting to configure GPIOs that we shouldn't
> > be configuring.
> 
> The driver is attempting to configure the GPIOs that device tree tells
> to.
> 
> 	led@3 {                        
> 		label = "apq8016-sbc:green:user3";
> 		gpios = <&pm8916_gpios 1 GPIO_ACTIVE_HIGH>;
> 		linux,default-trigger = "mmc1";
> 		default-state = "off";         
> 	};
> 
> Are you saying, in case of user3 led above, device tree shouldn't use
> GPIO <&pm8916_gpios 1> there at all?

Right. Does the GPIO work? If so, it sounds like the read/write
access checks in spmi pmic arb don't work properly.

> 
> > Is there some sort of default configuration that
> > gets applied to all pins by default?
> 
> I do not quite understand what you are asking and how that is related to
> the thing we discuss here.  But my understanding is that spmi_arb
> read/write access is used not only by pinctrl API to set up pinmux for
> GPIO function, but also by GPIO API to actually drive the GPIO.
> 

Ah I got confused because I thought we numbered GPIO pins from 0,
but on the PMIC we number from 1. I see that base = -1 assignment
now. I thought that all pins on the pmic were being configured
somewhere because I didn't see a gpio 0 usage in DT.

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Shawn Guo]

On Fri, Aug 25, 2017 at 04:18:18PM -0700, Stephen Boyd wrote:
> On 08/25, Shawn Guo wrote:
> > On Thu, Aug 24, 2017 at 11:37:01AM -0700, Stephen Boyd wrote:
> > > On 08/24, Shawn Guo wrote:
> > > > On Tue, Aug 22, 2017 at 01:31:32PM -0700, Stephen Boyd wrote:
> > > > > Also, I see that on v4.13-rc series the read/write checks are
> > > > > causing the led driver to fail in a different way:
> > > > > 
> > > > >     spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc040
> > > > >     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x40 failed
> > > > >     leds-gpio soc:leds: Error applying setting, reverse things back
> > > > >     spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc041
> > > > >     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x41 failed
> > > > >     leds-gpio: probe of soc:leds failed with error -1 
> > > > > 
> > > > > Are you seeing similar behavior?
> > > > 
> > > > Yes.  I forgot to mention that, and leds-gpio failure is gone after
> > > > applying Kiran's patch below.
> > > > 
> > > > spmi: pmic-arb: remove the read/write access checks
> > > > 
> > > 
> > > Sure. Removing the checks will silence the warnings, but it still
> > > means that we're attempting to configure GPIOs that we shouldn't
> > > be configuring.
> > 
> > The driver is attempting to configure the GPIOs that device tree tells
> > to.
> > 
> > 	led@3 {                        
> > 		label = "apq8016-sbc:green:user3";
> > 		gpios = <&pm8916_gpios 1 GPIO_ACTIVE_HIGH>;
> > 		linux,default-trigger = "mmc1";
> > 		default-state = "off";         
> > 	};
> > 
> > Are you saying, in case of user3 led above, device tree shouldn't use
> > GPIO <&pm8916_gpios 1> there at all?
> 
> Right. Does the GPIO work? If so, it sounds like the read/write
> access checks in spmi pmic arb don't work properly.

The check works.  With the check in there, PM8916 GPIO doesn't work.
However, the consequence is that not only user3 but all GPIO leds under
'leds' node will fail to register, because any GPIO led's failing on
create_gpio_led() makes leds-gpio driver probe fail as a while.  That's
how leds-gpio driver works.

Also, per schematics, PM8916 GPIO1 is indeed routed to user3 LED on
db410c board.  Why do you think apq8016-sbc device tree shouldn't use
the GPIO for that at all?  Isn't it firmware's fault that the ownership
of the peripheral is not properly configured?

Shawn
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Shawn Guo]

On Fri, Aug 25, 2017 at 04:18:18PM -0700, Stephen Boyd wrote:
> On 08/25, Shawn Guo wrote:
> > On Thu, Aug 24, 2017 at 11:37:01AM -0700, Stephen Boyd wrote:
> > > On 08/24, Shawn Guo wrote:
> > > > On Tue, Aug 22, 2017 at 01:31:32PM -0700, Stephen Boyd wrote:
> > > > > Also, I see that on v4.13-rc series the read/write checks are
> > > > > causing the led driver to fail in a different way:
> > > > > 
> > > > >     spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc040
> > > > >     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x40 failed
> > > > >     leds-gpio soc:leds: Error applying setting, reverse things back
> > > > >     spmi spmi-0: error: impermissible write to peripheral sid:0 addr:0xc041
> > > > >     qcom-spmi-gpio 200f000.spmi:pm8916@0:gpios@c000: write 0x41 failed
> > > > >     leds-gpio: probe of soc:leds failed with error -1 
> > > > > 
> > > > > Are you seeing similar behavior?
> > > > 
> > > > Yes.  I forgot to mention that, and leds-gpio failure is gone after
> > > > applying Kiran's patch below.
> > > > 
> > > > spmi: pmic-arb: remove the read/write access checks
> > > > 
> > > 
> > > Sure. Removing the checks will silence the warnings, but it still
> > > means that we're attempting to configure GPIOs that we shouldn't
> > > be configuring.
> > 
> > The driver is attempting to configure the GPIOs that device tree tells
> > to.
> > 
> > 	led@3 {                        
> > 		label = "apq8016-sbc:green:user3";
> > 		gpios = <&pm8916_gpios 1 GPIO_ACTIVE_HIGH>;
> > 		linux,default-trigger = "mmc1";
> > 		default-state = "off";         
> > 	};
> > 
> > Are you saying, in case of user3 led above, device tree shouldn't use
> > GPIO <&pm8916_gpios 1> there at all?
> 
> Right. Does the GPIO work? If so, it sounds like the read/write
> access checks in spmi pmic arb don't work properly.

The check works.  With the check in there, PM8916 GPIO doesn't work.
However, the consequence is that not only user3 but all GPIO leds under
'leds' node will fail to register, because any GPIO led's failing on
create_gpio_led() makes leds-gpio driver probe fail as a while.  That's
how leds-gpio driver works.

Also, per schematics, PM8916 GPIO1 is indeed routed to user3 LED on
db410c board.  Why do you think apq8016-sbc device tree shouldn't use
the GPIO for that at all?  Isn't it firmware's fault that the ownership
of the peripheral is not properly configured?

Shawn

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Fenglin Wu]

On 8/22/2017 4:55 PM, Shawn Guo wrote:
> On Mon, Aug 21, 2017 at 04:18:58PM -0700, Stephen Boyd wrote:
>> On 08/18/2017 08:28 AM, Kiran Gunda wrote:
>>> The peripheral ownership check is not necessary on single master
>>> platforms. Hence, enforce the peripheral ownership check optionally.
>>>
>>> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
>>> Tested-by: Shawn Guo <shawnguo@kernel.org>
>>> ---
>>
>> This sounds like a band-aid. Isn't the gpio driver going to keep probing
>> all the pins that are not supposed to be accessed due to security
>> constraints? What exactly is failing in the gpio case?
> 
> There is a platform_irq_count() call in pinctrl-spmi-gpio probe
> function.  Due to the owner check in spmi-pmic-arb IRQ domain
> qpnpint_irq_domain_dt_translate() function, the call will return irq
> number as zero and cause pmic_gpio_probe() fail with -EINVAL error.
> 
> [    1.608516] [<ffff00000860e51c>] qpnpint_irq_domain_dt_translate+0x168/0x194
> [    1.613557] [<ffff000008117040>] irq_create_fwspec_mapping+0x17c/0x2d8
> [    1.620672] [<ffff000008117200>] irq_create_of_mapping+0x64/0x74
> [    1.627008] [<ffff0000087b4fac>] of_irq_get+0x54/0x64
> [    1.633169] [<ffff00000856b824>] platform_get_irq+0x20/0x150
> [    1.638117] [<ffff00000856b97c>] platform_irq_count+0x28/0x44
> [    1.643850] [<ffff0000083cf12c>] pmic_gpio_probe+0x50/0x544
> 
> ShawnI just realize this patch is trying to fix this issue from spmi driver
level. Actually I had submitted a change in spmi-gpio driver to fix
this by ignoring the GPIOs which the IRQ is not owned by APPS
processor. The maintainer hasn't reviewed it yet:
https://www.spinics.net/lists/linux-arm-msm/msg28849.html
I am trying to understand if my patch is still needed if Kiran's patch
get merged, the intention for my patch originally is for fixing the same
probe failure, but it could hide the GPIOs which are not allowed to use
from the pinctrl driver level. Please help to suggest.
Thanks

Fenglin

> --
> To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

-- 
Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project.

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Greg KH]

On Fri, Aug 18, 2017 at 08:58:29PM +0530, Kiran Gunda wrote:
> The peripheral ownership check is not necessary on single master
> platforms. Hence, enforce the peripheral ownership check optionally.
> 
> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
> Tested-by: Shawn Guo <shawnguo@kernel.org>
> ---
> v2:
> 	Fixed the commit message.
> 	Added Shawn's 'Tested-by' tag.
> 
> v1:
> 	This patch depends on the below patch series. Please take this patch
> 	along with this series.
> 
> 	[PATCH V2 00/12]: spmi: pmic-arb: Support for HW v5 and other fixes
> 
>  Documentation/devicetree/bindings/spmi/qcom,spmi-pmic-arb.txt | 6 ++++++
>  drivers/spmi/spmi-pmic-arb.c                                  | 7 ++++++-
>  2 files changed, 12 insertions(+), 1 deletion(-)

This doesn't apply on top of the other spmi patches I just added to my
tree.  Did I mess something up here?

thanks,

greg k-h

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Shawn Guo]

On Mon, Aug 28, 2017 at 01:53:28PM +0200, Greg KH wrote:
> On Fri, Aug 18, 2017 at 08:58:29PM +0530, Kiran Gunda wrote:
> > The peripheral ownership check is not necessary on single master
> > platforms. Hence, enforce the peripheral ownership check optionally.
> > 
> > Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
> > Tested-by: Shawn Guo <shawnguo@kernel.org>
> > ---
> > v2:
> > 	Fixed the commit message.
> > 	Added Shawn's 'Tested-by' tag.
> > 
> > v1:
> > 	This patch depends on the below patch series. Please take this patch
> > 	along with this series.
> > 
> > 	[PATCH V2 00/12]: spmi: pmic-arb: Support for HW v5 and other fixes
> > 
> >  Documentation/devicetree/bindings/spmi/qcom,spmi-pmic-arb.txt | 6 ++++++
> >  drivers/spmi/spmi-pmic-arb.c                                  | 7 ++++++-
> >  2 files changed, 12 insertions(+), 1 deletion(-)
> 
> This doesn't apply on top of the other spmi patches I just added to my
> tree.  Did I mess something up here?

Sorry, Greg.  We should have told you that this patch is obsolete and
replaced by the one below, which you just applied to char-misc-testing.

  spmi: pmic-arb: Move the ownership check to irq_chip callback

Shawn

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Shawn Guo]

On Mon, Aug 28, 2017 at 04:27:54PM +0800, Fenglin Wu wrote:
> On 8/22/2017 4:55 PM, Shawn Guo wrote:
> >On Mon, Aug 21, 2017 at 04:18:58PM -0700, Stephen Boyd wrote:
> >>On 08/18/2017 08:28 AM, Kiran Gunda wrote:
> >>>The peripheral ownership check is not necessary on single master
> >>>platforms. Hence, enforce the peripheral ownership check optionally.
> >>>
> >>>Signed-off-by: Kiran Gunda <kgunda-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
> >>>Tested-by: Shawn Guo <shawnguo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> >>>---
> >>
> >>This sounds like a band-aid. Isn't the gpio driver going to keep probing
> >>all the pins that are not supposed to be accessed due to security
> >>constraints? What exactly is failing in the gpio case?
> >
> >There is a platform_irq_count() call in pinctrl-spmi-gpio probe
> >function.  Due to the owner check in spmi-pmic-arb IRQ domain
> >qpnpint_irq_domain_dt_translate() function, the call will return irq
> >number as zero and cause pmic_gpio_probe() fail with -EINVAL error.
> >
> >[    1.608516] [<ffff00000860e51c>] qpnpint_irq_domain_dt_translate+0x168/0x194
> >[    1.613557] [<ffff000008117040>] irq_create_fwspec_mapping+0x17c/0x2d8
> >[    1.620672] [<ffff000008117200>] irq_create_of_mapping+0x64/0x74
> >[    1.627008] [<ffff0000087b4fac>] of_irq_get+0x54/0x64
> >[    1.633169] [<ffff00000856b824>] platform_get_irq+0x20/0x150
> >[    1.638117] [<ffff00000856b97c>] platform_irq_count+0x28/0x44
> >[    1.643850] [<ffff0000083cf12c>] pmic_gpio_probe+0x50/0x544
> >
> >ShawnI just realize this patch is trying to fix this issue from spmi driver
> level. Actually I had submitted a change in spmi-gpio driver to fix
> this by ignoring the GPIOs which the IRQ is not owned by APPS
> processor. The maintainer hasn't reviewed it yet:
> https://www.spinics.net/lists/linux-arm-msm/msg28849.html
> I am trying to understand if my patch is still needed if Kiran's patch
> get merged, the intention for my patch originally is for fixing the same
> probe failure, but it could hide the GPIOs which are not allowed to use
> from the pinctrl driver level. Please help to suggest.

As I just replied to Greg, this patch is obsolete and replaced by 'spmi:
pmic-arb: Move the ownership check to irq_chip callback' [1].

With the patch applied, we can get rid of the spmi-gpio probe failure.
So from the point of fixing the issue, your patch is not needed.  But I
would like to discuss your patch a bit, and will reply to your patch
with my comments.

Shawn

[1] https://lkml.org/lkml/2017/8/23/325
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Shawn Guo]

On Mon, Aug 28, 2017 at 04:27:54PM +0800, Fenglin Wu wrote:
> On 8/22/2017 4:55 PM, Shawn Guo wrote:
> >On Mon, Aug 21, 2017 at 04:18:58PM -0700, Stephen Boyd wrote:
> >>On 08/18/2017 08:28 AM, Kiran Gunda wrote:
> >>>The peripheral ownership check is not necessary on single master
> >>>platforms. Hence, enforce the peripheral ownership check optionally.
> >>>
> >>>Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
> >>>Tested-by: Shawn Guo <shawnguo@kernel.org>
> >>>---
> >>
> >>This sounds like a band-aid. Isn't the gpio driver going to keep probing
> >>all the pins that are not supposed to be accessed due to security
> >>constraints? What exactly is failing in the gpio case?
> >
> >There is a platform_irq_count() call in pinctrl-spmi-gpio probe
> >function.  Due to the owner check in spmi-pmic-arb IRQ domain
> >qpnpint_irq_domain_dt_translate() function, the call will return irq
> >number as zero and cause pmic_gpio_probe() fail with -EINVAL error.
> >
> >[    1.608516] [<ffff00000860e51c>] qpnpint_irq_domain_dt_translate+0x168/0x194
> >[    1.613557] [<ffff000008117040>] irq_create_fwspec_mapping+0x17c/0x2d8
> >[    1.620672] [<ffff000008117200>] irq_create_of_mapping+0x64/0x74
> >[    1.627008] [<ffff0000087b4fac>] of_irq_get+0x54/0x64
> >[    1.633169] [<ffff00000856b824>] platform_get_irq+0x20/0x150
> >[    1.638117] [<ffff00000856b97c>] platform_irq_count+0x28/0x44
> >[    1.643850] [<ffff0000083cf12c>] pmic_gpio_probe+0x50/0x544
> >
> >ShawnI just realize this patch is trying to fix this issue from spmi driver
> level. Actually I had submitted a change in spmi-gpio driver to fix
> this by ignoring the GPIOs which the IRQ is not owned by APPS
> processor. The maintainer hasn't reviewed it yet:
> https://www.spinics.net/lists/linux-arm-msm/msg28849.html
> I am trying to understand if my patch is still needed if Kiran's patch
> get merged, the intention for my patch originally is for fixing the same
> probe failure, but it could hide the GPIOs which are not allowed to use
> from the pinctrl driver level. Please help to suggest.

As I just replied to Greg, this patch is obsolete and replaced by 'spmi:
pmic-arb: Move the ownership check to irq_chip callback' [1].

With the patch applied, we can get rid of the spmi-gpio probe failure.
So from the point of fixing the issue, your patch is not needed.  But I
would like to discuss your patch a bit, and will reply to your patch
with my comments.

Shawn

[1] https://lkml.org/lkml/2017/8/23/325

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Stephen Boyd]

On 08/26, Shawn Guo wrote:
> On Fri, Aug 25, 2017 at 04:18:18PM -0700, Stephen Boyd wrote:
> > 
> > Right. Does the GPIO work? If so, it sounds like the read/write
> > access checks in spmi pmic arb don't work properly.
> 
> The check works.  With the check in there, PM8916 GPIO doesn't work.
> However, the consequence is that not only user3 but all GPIO leds under
> 'leds' node will fail to register, because any GPIO led's failing on
> create_gpio_led() makes leds-gpio driver probe fail as a while.  That's
> how leds-gpio driver works.
> 
> Also, per schematics, PM8916 GPIO1 is indeed routed to user3 LED on
> db410c board.  Why do you think apq8016-sbc device tree shouldn't use
> the GPIO for that at all?  Isn't it firmware's fault that the ownership
> of the peripheral is not properly configured?

If the ownership was not properly configured in the firmware,
then I imagine it would mean that we can't control the GPIO for
the LED. But that doesn't seem to be true. I can see on my board
that I get impermissible write failures on the GPIO when
controlling the GPIO brightness, but it doesn't actually matter
because the led still lights up. So the checks for write/read
permission seem incorrect, or they're not being enforced.

Anyway, I just wanted to make sure the GPIO still works, and it
looks like it does, so removing the permission checks is enough
to make me happy.

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Stephen Boyd]

On 08/26, Shawn Guo wrote:
> On Fri, Aug 25, 2017 at 04:18:18PM -0700, Stephen Boyd wrote:
> > 
> > Right. Does the GPIO work? If so, it sounds like the read/write
> > access checks in spmi pmic arb don't work properly.
> 
> The check works.  With the check in there, PM8916 GPIO doesn't work.
> However, the consequence is that not only user3 but all GPIO leds under
> 'leds' node will fail to register, because any GPIO led's failing on
> create_gpio_led() makes leds-gpio driver probe fail as a while.  That's
> how leds-gpio driver works.
> 
> Also, per schematics, PM8916 GPIO1 is indeed routed to user3 LED on
> db410c board.  Why do you think apq8016-sbc device tree shouldn't use
> the GPIO for that at all?  Isn't it firmware's fault that the ownership
> of the peripheral is not properly configured?

If the ownership was not properly configured in the firmware,
then I imagine it would mean that we can't control the GPIO for
the LED. But that doesn't seem to be true. I can see on my board
that I get impermissible write failures on the GPIO when
controlling the GPIO brightness, but it doesn't actually matter
because the led still lights up. So the checks for write/read
permission seem incorrect, or they're not being enforced.

Anyway, I just wanted to make sure the GPIO still works, and it
looks like it does, so removing the permission checks is enough
to make me happy.

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Shawn Guo]

On Wed, Aug 30, 2017 at 02:02:03PM -0700, Stephen Boyd wrote:
> On 08/26, Shawn Guo wrote:
> > On Fri, Aug 25, 2017 at 04:18:18PM -0700, Stephen Boyd wrote:
> > > 
> > > Right. Does the GPIO work? If so, it sounds like the read/write
> > > access checks in spmi pmic arb don't work properly.
> > 
> > The check works.  With the check in there, PM8916 GPIO doesn't work.
> > However, the consequence is that not only user3 but all GPIO leds under
> > 'leds' node will fail to register, because any GPIO led's failing on
> > create_gpio_led() makes leds-gpio driver probe fail as a while.  That's
> > how leds-gpio driver works.
> > 
> > Also, per schematics, PM8916 GPIO1 is indeed routed to user3 LED on
> > db410c board.  Why do you think apq8016-sbc device tree shouldn't use
> > the GPIO for that at all?  Isn't it firmware's fault that the ownership
> > of the peripheral is not properly configured?
> 
> If the ownership was not properly configured in the firmware,
> then I imagine it would mean that we can't control the GPIO for
> the LED. But that doesn't seem to be true. I can see on my board
> that I get impermissible write failures on the GPIO when
> controlling the GPIO brightness, but it doesn't actually matter
> because the led still lights up. So the checks for write/read
> permission seem incorrect, or they're not being enforced.

I'm not sure what is happening on your side.  As I said above, with the
4.13-rc series, leds-gpio driver doesn't probe at all, due to the
impermissible write to PM8916 GPIO in function create_gpio_led(), and
none of the LEDs lights up on my board.

Shawn

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Stephen Boyd]

On 08/31, Shawn Guo wrote:
> On Wed, Aug 30, 2017 at 02:02:03PM -0700, Stephen Boyd wrote:
> > On 08/26, Shawn Guo wrote:
> > > On Fri, Aug 25, 2017 at 04:18:18PM -0700, Stephen Boyd wrote:
> > > > 
> > > > Right. Does the GPIO work? If so, it sounds like the read/write
> > > > access checks in spmi pmic arb don't work properly.
> > > 
> > > The check works.  With the check in there, PM8916 GPIO doesn't work.
> > > However, the consequence is that not only user3 but all GPIO leds under
> > > 'leds' node will fail to register, because any GPIO led's failing on
> > > create_gpio_led() makes leds-gpio driver probe fail as a while.  That's
> > > how leds-gpio driver works.
> > > 
> > > Also, per schematics, PM8916 GPIO1 is indeed routed to user3 LED on
> > > db410c board.  Why do you think apq8016-sbc device tree shouldn't use
> > > the GPIO for that at all?  Isn't it firmware's fault that the ownership
> > > of the peripheral is not properly configured?
> > 
> > If the ownership was not properly configured in the firmware,
> > then I imagine it would mean that we can't control the GPIO for
> > the LED. But that doesn't seem to be true. I can see on my board
> > that I get impermissible write failures on the GPIO when
> > controlling the GPIO brightness, but it doesn't actually matter
> > because the led still lights up. So the checks for write/read
> > permission seem incorrect, or they're not being enforced.
> 
> I'm not sure what is happening on your side.  As I said above, with the
> 4.13-rc series, leds-gpio driver doesn't probe at all, due to the
> impermissible write to PM8916 GPIO in function create_gpio_led(), and
> none of the LEDs lights up on my board.
> 

Yep. I understand all that.

Sorry, I forgot to mention I modified the SPMI PMIC arb code on
v4.13-rc7 to continue even though a permission fault may happen
by deleting the 'return -EPERM' lines. So the LED GPIO driver is
still probing for me, and I see that the GPIOs work regardless of
any permission problems that may have been enforced in the
hardware. I thought the permission checks that the software is
looking at to return EPERM were enforced in hardware, but that
doesn't seem to be the case. That's all I was wondering about.

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Shawn Guo]

On Thu, Aug 31, 2017 at 06:30:48PM -0700, Stephen Boyd wrote:
> On 08/31, Shawn Guo wrote:
> > On Wed, Aug 30, 2017 at 02:02:03PM -0700, Stephen Boyd wrote:
> > > On 08/26, Shawn Guo wrote:
> > > > On Fri, Aug 25, 2017 at 04:18:18PM -0700, Stephen Boyd wrote:
> > > > > 
> > > > > Right. Does the GPIO work? If so, it sounds like the read/write
> > > > > access checks in spmi pmic arb don't work properly.
> > > > 
> > > > The check works.  With the check in there, PM8916 GPIO doesn't work.
> > > > However, the consequence is that not only user3 but all GPIO leds under
> > > > 'leds' node will fail to register, because any GPIO led's failing on
> > > > create_gpio_led() makes leds-gpio driver probe fail as a while.  That's
> > > > how leds-gpio driver works.
> > > > 
> > > > Also, per schematics, PM8916 GPIO1 is indeed routed to user3 LED on
> > > > db410c board.  Why do you think apq8016-sbc device tree shouldn't use
> > > > the GPIO for that at all?  Isn't it firmware's fault that the ownership
> > > > of the peripheral is not properly configured?
> > > 
> > > If the ownership was not properly configured in the firmware,
> > > then I imagine it would mean that we can't control the GPIO for
> > > the LED. But that doesn't seem to be true. I can see on my board
> > > that I get impermissible write failures on the GPIO when
> > > controlling the GPIO brightness, but it doesn't actually matter
> > > because the led still lights up. So the checks for write/read
> > > permission seem incorrect, or they're not being enforced.
> > 
> > I'm not sure what is happening on your side.  As I said above, with the
> > 4.13-rc series, leds-gpio driver doesn't probe at all, due to the
> > impermissible write to PM8916 GPIO in function create_gpio_led(), and
> > none of the LEDs lights up on my board.
> > 
> 
> Yep. I understand all that.
> 
> Sorry, I forgot to mention I modified the SPMI PMIC arb code on
> v4.13-rc7 to continue even though a permission fault may happen
> by deleting the 'return -EPERM' lines. So the LED GPIO driver is
> still probing for me, and I see that the GPIOs work regardless of
> any permission problems that may have been enforced in the
> hardware. I thought the permission checks that the software is
> looking at to return EPERM were enforced in hardware, but that
> doesn't seem to be the case. That's all I was wondering about.

Ah, okay.  You were asking about the check in hardware, while I was
talking about the check in software.  Yes, now we are on the same page:
the permission check in hardware seems not enforced.  That's why LED
works after we merely remove the check in SPMI PMIC arb driver code.

Shawn
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally

[Shawn Guo]

On Thu, Aug 31, 2017 at 06:30:48PM -0700, Stephen Boyd wrote:
> On 08/31, Shawn Guo wrote:
> > On Wed, Aug 30, 2017 at 02:02:03PM -0700, Stephen Boyd wrote:
> > > On 08/26, Shawn Guo wrote:
> > > > On Fri, Aug 25, 2017 at 04:18:18PM -0700, Stephen Boyd wrote:
> > > > > 
> > > > > Right. Does the GPIO work? If so, it sounds like the read/write
> > > > > access checks in spmi pmic arb don't work properly.
> > > > 
> > > > The check works.  With the check in there, PM8916 GPIO doesn't work.
> > > > However, the consequence is that not only user3 but all GPIO leds under
> > > > 'leds' node will fail to register, because any GPIO led's failing on
> > > > create_gpio_led() makes leds-gpio driver probe fail as a while.  That's
> > > > how leds-gpio driver works.
> > > > 
> > > > Also, per schematics, PM8916 GPIO1 is indeed routed to user3 LED on
> > > > db410c board.  Why do you think apq8016-sbc device tree shouldn't use
> > > > the GPIO for that at all?  Isn't it firmware's fault that the ownership
> > > > of the peripheral is not properly configured?
> > > 
> > > If the ownership was not properly configured in the firmware,
> > > then I imagine it would mean that we can't control the GPIO for
> > > the LED. But that doesn't seem to be true. I can see on my board
> > > that I get impermissible write failures on the GPIO when
> > > controlling the GPIO brightness, but it doesn't actually matter
> > > because the led still lights up. So the checks for write/read
> > > permission seem incorrect, or they're not being enforced.
> > 
> > I'm not sure what is happening on your side.  As I said above, with the
> > 4.13-rc series, leds-gpio driver doesn't probe at all, due to the
> > impermissible write to PM8916 GPIO in function create_gpio_led(), and
> > none of the LEDs lights up on my board.
> > 
> 
> Yep. I understand all that.
> 
> Sorry, I forgot to mention I modified the SPMI PMIC arb code on
> v4.13-rc7 to continue even though a permission fault may happen
> by deleting the 'return -EPERM' lines. So the LED GPIO driver is
> still probing for me, and I see that the GPIOs work regardless of
> any permission problems that may have been enforced in the
> hardware. I thought the permission checks that the software is
> looking at to return EPERM were enforced in hardware, but that
> doesn't seem to be the case. That's all I was wondering about.

Ah, okay.  You were asking about the check in hardware, while I was
talking about the check in software.  Yes, now we are on the same page:
the permission check in hardware seems not enforced.  That's why LED
works after we merely remove the check in SPMI PMIC arb driver code.

Shawn