[00/12] clocksource: improve Atmel TCB timer driver
mbox series

Message ID 20190403141120.32754-1-alexandre.belloni@bootlin.com
Headers show
Series
  • clocksource: improve Atmel TCB timer driver
Related show

Message

Alexandre Belloni April 3, 2019, 2:11 p.m. UTC
Hi,

This series immproves the Atmel TCB clocksource driver to address the
most urgent shortcomings:
 - the current tcb_clksrc driver is probed too late to be able to be used at
   boot and we now have SoCs that don't have a PIT. They currently are not able
   to boot an upstream kernel.
 - using the PIT doesn't work well with preempt-rt because its interrupt is
   shared (in particular with the UART) and their interrupt flags are
   incompatible). This also happen with the threadedirq command line
   switch.
 - there is currently no high resolution sched_clock.

The plan is to get those changes upstream as soon as possible as they
arre fixing real issues that people are facing. There are further
changes needed on the clocksource driver to try to stop wasting a TCB
channel.
the PWM TCB driver will also be changed to actually used the reviewed
binding and this will allow to get rif of atmel_tclib.

Alexandre Belloni (12):
  ARM: at91: move SoC specific definitions to SoC folder
  misc: atmel_tclib: drop AVR32 support
  misc: atmel_tclib: move definitions to header file
  clocksource/drivers/tcb_clksrc: stop depending on atmel_tclib
  clocksource/drivers/tcb_clksrc: Use tcb as sched_clock
  ARM: at91: Implement clocksource selection
  clocksource/drivers/tcb_clksrc: move Kconfig option
  clocksource/drivers/timer-atmel-pit: rework Kconfig option
  clocksource/drivers/tcb_clksrc: Rename the file for consistency
  ARM: configs: at91: unselect PIT
  misc: atmel_tclib: do not probe already used TCBs
  clocksource/drivers/timer-atmel-tcb: Use ARRAY_SIZE instead of  
    hardcoded size

 arch/arm/configs/at91_dt_defconfig            |   1 +
 arch/arm/configs/sama5_defconfig              |   1 +
 arch/arm/mach-at91/Kconfig                    |  23 ++++
 drivers/clocksource/Kconfig                   |  12 +-
 drivers/clocksource/Makefile                  |   2 +-
 .../{tcb_clksrc.c => timer-atmel-tcb.c}       | 123 ++++++++++++------
 drivers/misc/Kconfig                          |  24 ----
 drivers/misc/atmel_tclib.c                    |  37 +-----
 drivers/pwm/pwm-atmel-tcb.c                   |   2 +-
 .../atmel_tc.h => soc/at91/atmel_tcb.h}       |  25 +++-
 10 files changed, 146 insertions(+), 104 deletions(-)
 rename drivers/clocksource/{tcb_clksrc.c => timer-atmel-tcb.c} (81%)
 rename include/{linux/atmel_tc.h => soc/at91/atmel_tcb.h} (95%)

Comments

Daniel Lezcano April 11, 2019, 4:34 p.m. UTC | #1
Hi Alexandre,

except the comment for 3/12, the series looks good to me.



On 03/04/2019 16:11, Alexandre Belloni wrote:
> Hi,
> 
> This series immproves the Atmel TCB clocksource driver to address the
> most urgent shortcomings:
>  - the current tcb_clksrc driver is probed too late to be able to be used at
>    boot and we now have SoCs that don't have a PIT. They currently are not able
>    to boot an upstream kernel.
>  - using the PIT doesn't work well with preempt-rt because its interrupt is
>    shared (in particular with the UART) and their interrupt flags are
>    incompatible). This also happen with the threadedirq command line
>    switch.
>  - there is currently no high resolution sched_clock.
> 
> The plan is to get those changes upstream as soon as possible as they
> arre fixing real issues that people are facing. There are further
> changes needed on the clocksource driver to try to stop wasting a TCB
> channel.
> the PWM TCB driver will also be changed to actually used the reviewed
> binding and this will allow to get rif of atmel_tclib.
> 
> Alexandre Belloni (12):
>   ARM: at91: move SoC specific definitions to SoC folder
>   misc: atmel_tclib: drop AVR32 support
>   misc: atmel_tclib: move definitions to header file
>   clocksource/drivers/tcb_clksrc: stop depending on atmel_tclib
>   clocksource/drivers/tcb_clksrc: Use tcb as sched_clock
>   ARM: at91: Implement clocksource selection
>   clocksource/drivers/tcb_clksrc: move Kconfig option
>   clocksource/drivers/timer-atmel-pit: rework Kconfig option
>   clocksource/drivers/tcb_clksrc: Rename the file for consistency
>   ARM: configs: at91: unselect PIT
>   misc: atmel_tclib: do not probe already used TCBs
>   clocksource/drivers/timer-atmel-tcb: Use ARRAY_SIZE instead of  
>     hardcoded size
> 
>  arch/arm/configs/at91_dt_defconfig            |   1 +
>  arch/arm/configs/sama5_defconfig              |   1 +
>  arch/arm/mach-at91/Kconfig                    |  23 ++++
>  drivers/clocksource/Kconfig                   |  12 +-
>  drivers/clocksource/Makefile                  |   2 +-
>  .../{tcb_clksrc.c => timer-atmel-tcb.c}       | 123 ++++++++++++------
>  drivers/misc/Kconfig                          |  24 ----
>  drivers/misc/atmel_tclib.c                    |  37 +-----
>  drivers/pwm/pwm-atmel-tcb.c                   |   2 +-
>  .../atmel_tc.h => soc/at91/atmel_tcb.h}       |  25 +++-
>  10 files changed, 146 insertions(+), 104 deletions(-)
>  rename drivers/clocksource/{tcb_clksrc.c => timer-atmel-tcb.c} (81%)
>  rename include/{linux/atmel_tc.h => soc/at91/atmel_tcb.h} (95%)
>