target/linux/bcm27xx/patches-5.10/950-0589-overlays-README-improve-the-gpio-poweroff-guide.patch

   1 From 81fe79da00f4130ef329d22d6b9433f1ff7f2b6f Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.com>
   3 Date: Mon, 26 Apr 2021 09:58:14 +0100
   4 Subject: [PATCH] overlays: README - improve the gpio-poweroff guide
   5
   6 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
   7 ---
   8  arch/arm/boot/dts/overlays/README | 11 +++++++++--
   9  1 file changed, 9 insertions(+), 2 deletions(-)
  10
  11 --- a/arch/arm/boot/dts/overlays/README
  12 +++ b/arch/arm/boot/dts/overlays/README
  13 @@ -987,8 +987,15 @@ Params: <None>
  14
  15
  16  Name:   gpio-poweroff
  17 -Info:   Drives a GPIO high or low on poweroff (including halt). Enabling this
  18 -        overlay will prevent the ability to boot by driving GPIO3 low.
  19 +Info:   Drives a GPIO high or low on poweroff (including halt). Using this
  20 +        overlay interferes with the normal power-down sequence, preventing the
  21 +        kernel from resetting the SoC (a necessary step in a normal power-off
  22 +        or reboot). This also disables the ability to triger a boot by driving
  23 +        GPIO3 low.
  24 +
  25 +        Users of this overlay are required to provide an external mechanism to
  26 +        switch off the power supply when signalled - failure to do so results
  27 +        in a kernel BUG, increased power consumption and undefined behaviour.
  28  Load:   dtoverlay=gpio-poweroff,<param>=<val>
  29  Params: gpiopin                 GPIO for signalling (default 26)
  30