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

From: Fenglin Wu
Date: Mon Aug 28 2017 - 04:28:08 EST


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@xxxxxxxxxxxxxx>
Tested-by: Shawn Guo <shawnguo@xxxxxxxxxx>
---

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@xxxxxxxxxxxxxxx
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.