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SubjectRe: [PATCH v4 0/5] Support qcom pinctrl protected pins
From
Date
On Fri, 2018-03-23 at 09:34 -0700, Stephen Boyd wrote:
> This patchset proposes a solution to describing the
> valid
>
> pins for a pin controller in a generic way so that
> qcom
>
> platforms can expose the pins that are really
> available.
>
>
>
> Typically, this has been done by having drivers and
> firmware
>
> descriptions only use pins they know they have access to, and
> that
> still works now because we no longer read the pin direction
> at
>
> boot. But there are still some userspace drivers and debugfs
> facilities
>
> that don't know what pins are available and attempt to read
> everything
>
> they can. On qcom platforms, this may lead to a system hang, which
> isn't
> very nice behavior, even if root is the only user that can trigger
> it.
>
>
> The proposal is to describe the valid pins and then not allow things
> to
> cause problems by using the invalid pins. Obviously, the firmware
> may
> mess this up, so this is mostly a nice to have feature or a safety
> net
> so that things don't blow up
> easily.

FWIW,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>


> Changes from v3:
> * Split out allocation of mask into subroutine
> * Moved that allocation to kmalloc_array()
> * Updated qcom driver to simplifiy ACPI logic and fix mem leak
>
> Changes from v2:
> * Renamed binding to 'gpio-reserved-ranges'
> * Reworked gpiolib patch to not use irqdomains
> * Update qcom driver patch to use new valid_mask field
>
>
> Changes from
> v1:
>
> * Pushed into gpiolib-of core under irq valid line
> logic
>
> * Fixed up qcom driver patch to free stuff properly and remove custom
> code
> * Dropped export patch as it got picked
> up
>
> * Renamed binding to 'reserved-gpio-ranges'
>
>
> Stephen Boyd (5):
> dt-bindings: gpio: Add a gpio-reserved-ranges property
> gpiolib: Extract mask allocation into subroutine
> gpiolib: Change bitmap allocation to kmalloc_array
> gpiolib: Support 'gpio-reserved-ranges' property
> pinctrl: qcom: Don't allow protected pins to be requested
>
> .../devicetree/bindings/gpio/gpio.txt | 7 +-
> drivers/gpio/gpiolib-of.c | 24 +++++++
> drivers/gpio/gpiolib.c | 66 +++++++++++++++++-
> -
> drivers/pinctrl/qcom/pinctrl-msm.c | 65 +++++++++++++++++-
> include/linux/gpio/driver.h | 16 +++++
> 5 files changed, 167 insertions(+), 11 deletions(-)
>

--
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy

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