Re: [PATCH 00/23] ARM: at91: Properly handle slow clock

Hi,

I realize now that I forgot to add the v2 tag in the subject lines. This
is really v2 :)

On 31/07/2015 at 11:39:36 +0200, Alexandre Belloni wrote :

Hi,

It was discovered that all the slow clock user were not properly claiming it.
This can end up in a system hang because the last registered user is releasing
it, and it gets disabled.

commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system hang")
was a workaround. This series is adding the slow clock to the necessary drivers
to avoid the issue and then removes that workaround.

The Documentation updates and DT patches should probably go through the AT91
tree this cycle to avoid breakage.

Then the other patches can go through each subsystem tree. They are trivial
enough to also go in this cycle.

The final clk patch depends on the other ones and may be taken for the next
cycle to avoid synchronization issues.

I've thrown in a cleanup for at91-reset as it avoids adding support for that
clock to the platform data initialization

Changes in v2:
 - statisticize the global in the atmel-st change
 - merge at91_reset_of_probe() in at91_reset_probe()
 - added patches from Boris for the TCB
 - added the slow clock to the TCB

Cc: Alessandro Zummo <redacted>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Lezcano <redacted>
Cc: Dmitry Eremin-Solenikov <redacted>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-clk@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-pwm@vger.kernel.org
Cc: linux-watchdog@vger.kernel.org
Cc: Michael Turquette <redacted>
Cc: rtc-linux@googlegroups.com
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Stephen Boyd <redacted>
Cc: Thierry Reding <redacted>
Cc: Thomas Gleixner <redacted>
Cc: Wim Van Sebroeck <redacted>

Alexandre Belloni (20):
  Documentation: dt: atmel-at91: add clocks to system timer, rstc and
    shdwc
  Documentation: watchdog: at91sam9_wdt: add clocks property
  Documentation: dt: rtc: at91rm9200: add clocks property
  ARM: at91/dt: at91rm9200: use slow clock where necessary
  ARM: at91/dt: at91sam9260: use slow clock where necessary
  ARM: at91/dt: at91sam9261: use slow clock where necessary
  ARM: at91/dt: at91sam9263: use slow clock where necessary
  ARM: at91/dt: at91sam9g45: use slow clock where necessary
  ARM: at91/dt: at91sam9n12: use slow clock where necessary
  ARM: at91/dt: at91sam9rl: use slow clock where necessary
  ARM: at91/dt: at91sam9x5: use slow clock where necessary
  ARM: at91/dt: sama5d3: use slow clock where necessary
  ARM: at91/dt: sama5d4: use slow clock where necessary
  rtc: at91rm9200: get and use slow clock
  watchdog: at91sam9: get and use slow clock
  power/reset: at91-reset: remove useless at91_reset_platform_probe()
  power/reset: at91-reset: get and use slow clock
  power/reset: at91-poweroff: get and use slow clock
  clocksource: atmel-st: get and use slow clock
  clk: at91: Revert "keep slow clk enabled to prevent system hang"

Boris Brezillon (3):
  Documentation: dt: atmel-at91: add slow clock to tcb
  clocksource: tcb_clksrc: fix setup_clkevents error path
  misc: atmel_tclib: get and use slow clock

 .../devicetree/bindings/arm/atmel-at91.txt         | 13 +++--
 .../bindings/rtc/atmel,at91rm9200-rtc.txt          |  2 +
 .../devicetree/bindings/watchdog/atmel-wdt.txt     |  2 +
 arch/arm/boot/dts/at91rm9200.dtsi                  | 10 ++--
 arch/arm/boot/dts/at91sam9260.dtsi                 | 11 +++--
 arch/arm/boot/dts/at91sam9261.dtsi                 |  7 ++-
 arch/arm/boot/dts/at91sam9263.dtsi                 |  7 ++-
 arch/arm/boot/dts/at91sam9g45.dtsi                 | 12 +++--
 arch/arm/boot/dts/at91sam9n12.dtsi                 | 12 +++--
 arch/arm/boot/dts/at91sam9rl.dtsi                  |  8 ++-
 arch/arm/boot/dts/at91sam9x5.dtsi                  | 12 +++--
 arch/arm/boot/dts/sama5d3.dtsi                     |  8 ++-
 arch/arm/boot/dts/sama5d3_tcb1.dtsi                |  4 +-
 arch/arm/boot/dts/sama5d4.dtsi                     | 12 +++--
 drivers/clk/at91/clk-slow.c                        | 27 ----------
 drivers/clocksource/tcb_clksrc.c                   | 10 +++-
 drivers/clocksource/timer-atmel-st.c               | 31 ++++++++----
 drivers/misc/atmel_tclib.c                         |  4 ++
 drivers/power/reset/at91-poweroff.c                | 13 +++++
 drivers/power/reset/at91-reset.c                   | 57 ++++++----------------
 drivers/pwm/pwm-atmel-tcb.c                        | 23 ++++++---
 drivers/rtc/rtc-at91rm9200.c                       | 27 ++++++++--
 drivers/watchdog/at91sam9_wdt.c                    | 22 ++++++++-
 include/linux/atmel_tc.h                           |  1 +
 24 files changed, 206 insertions(+), 129 deletions(-)

-- 
2.1.4

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com