Re: [PATCH] clocksource: dw_apb_timer_of: support timer-based delay

2015-11-03 Thread Jisheng Zhang
Dear Arnd On Tue, 3 Nov 2015 09:49:32 +0100 Arnd Bergmann wrote: > On Tuesday 03 November 2015 14:59:40 Jisheng Zhang wrote: > > > On Monday 02 November 2015 11:03:34 Jisheng Zhang wrote: > > > > On Fri, 30 Oct 2015 13:42:01 +0100 Arnd Bergmann wrote: > > > I'd be happier with a solution th

Re: [PATCH] clocksource: dw_apb_timer_of: support timer-based delay

2015-11-03 Thread Arnd Bergmann
On Tuesday 03 November 2015 14:59:40 Jisheng Zhang wrote: > > On Monday 02 November 2015 11:03:34 Jisheng Zhang wrote: > > > On Fri, 30 Oct 2015 13:42:01 +0100 Arnd Bergmann wrote: > > I'd be happier with a solution that keeps the DT describing the hardware > > and not the way we expect Linux to

Re: [PATCH] clocksource: dw_apb_timer_of: support timer-based delay

2015-11-02 Thread Jisheng Zhang
Dear Arnd, On Mon, 2 Nov 2015 22:56:02 +0100 Arnd Bergmann wrote: > On Monday 02 November 2015 11:03:34 Jisheng Zhang wrote: > > On Fri, 30 Oct 2015 13:42:01 +0100 Arnd Bergmann wrote: > > > > > > This is not ideal from an overall maintenance perspective. We want to > > > be able to have a ker

Re: [PATCH] clocksource: dw_apb_timer_of: support timer-based delay

2015-11-02 Thread Arnd Bergmann
On Monday 02 November 2015 11:03:34 Jisheng Zhang wrote: > On Fri, 30 Oct 2015 13:42:01 +0100 Arnd Bergmann wrote: > > > > This is not ideal from an overall maintenance perspective. We want to > > be able to have a kernel with all drivers enabled that gives us the > > best behavior on all platform

Re: [PATCH] clocksource: dw_apb_timer_of: support timer-based delay

2015-11-02 Thread Arnd Bergmann
On Monday 02 November 2015 09:48:38 Daniel Lezcano wrote: > If I follow the logic of arch_arm_timer is better than dw_apb timer. > > 1. The arch_arm_timer is present > > => dw_apb timer is not used at all > > CONFIG_ARM_ARCH_TIMER=y > # CONFIG_DW_APB_TIMER is not set > > 2. The arch_arm_t

Re: [PATCH] clocksource: dw_apb_timer_of: support timer-based delay

2015-11-02 Thread Jisheng Zhang
Dear Daniel, On Mon, 2 Nov 2015 09:48:38 +0100 Daniel Lezcano wrote: > On 11/02/2015 03:51 AM, Jisheng Zhang wrote: > > Dear Daniel, > > > > On Fri, 30 Oct 2015 13:37:01 +0100 > > Daniel Lezcano wrote: > > > >> On 10/30/2015 12:09 PM, Jisheng Zhang wrote: > >>> Dear Daniel, > >>> > >>> On Fr

Re: [PATCH] clocksource: dw_apb_timer_of: support timer-based delay

2015-11-02 Thread Daniel Lezcano
On 11/02/2015 03:51 AM, Jisheng Zhang wrote: Dear Daniel, On Fri, 30 Oct 2015 13:37:01 +0100 Daniel Lezcano wrote: On 10/30/2015 12:09 PM, Jisheng Zhang wrote: Dear Daniel, On Fri, 30 Oct 2015 11:44:46 +0100 Daniel Lezcano wrote: On 10/30/2015 09:27 AM, Jisheng Zhang wrote: Implement an

Re: [PATCH] clocksource: dw_apb_timer_of: support timer-based delay

2015-11-01 Thread Jisheng Zhang
Dear Arnd and Daniel, On Fri, 30 Oct 2015 13:42:01 +0100 Arnd Bergmann wrote: > On Friday 30 October 2015 19:09:29 Jisheng Zhang wrote: > > > > diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig > > > > index a7726db..7b081805 100644 > > > > --- a/drivers/clocksource/Kconfig >

Re: [PATCH] clocksource: dw_apb_timer_of: support timer-based delay

2015-11-01 Thread Jisheng Zhang
Dear Daniel, On Fri, 30 Oct 2015 13:37:01 +0100 Daniel Lezcano wrote: > On 10/30/2015 12:09 PM, Jisheng Zhang wrote: > > Dear Daniel, > > > > On Fri, 30 Oct 2015 11:44:46 +0100 > > Daniel Lezcano wrote: > > > >> On 10/30/2015 09:27 AM, Jisheng Zhang wrote: > >>> Implement an ARM delay timer

Re: [PATCH] clocksource: dw_apb_timer_of: support timer-based delay

2015-10-30 Thread Arnd Bergmann
On Friday 30 October 2015 19:09:29 Jisheng Zhang wrote: > > > diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig > > > index a7726db..7b081805 100644 > > > --- a/drivers/clocksource/Kconfig > > > +++ b/drivers/clocksource/Kconfig > > > @@ -29,6 +29,16 @@ config DW_APB_TIMER_OF >

Re: [PATCH] clocksource: dw_apb_timer_of: support timer-based delay

2015-10-30 Thread Daniel Lezcano
On 10/30/2015 12:09 PM, Jisheng Zhang wrote: Dear Daniel, On Fri, 30 Oct 2015 11:44:46 +0100 Daniel Lezcano wrote: On 10/30/2015 09:27 AM, Jisheng Zhang wrote: Implement an ARM delay timer to be used for udelay(). This allows us to skip the delay loop calibration at boot on Marvell BG2, BG2Q

Re: [PATCH] clocksource: dw_apb_timer_of: support timer-based delay

2015-10-30 Thread Jisheng Zhang
Dear Daniel, On Fri, 30 Oct 2015 11:44:46 +0100 Daniel Lezcano wrote: > On 10/30/2015 09:27 AM, Jisheng Zhang wrote: > > Implement an ARM delay timer to be used for udelay(). This allows us to > > skip the delay loop calibration at boot on Marvell BG2, BG2Q, BG2CD > > platforms. And after this p

Re: [PATCH] clocksource: dw_apb_timer_of: support timer-based delay

2015-10-30 Thread Daniel Lezcano
On 10/30/2015 09:27 AM, Jisheng Zhang wrote: Implement an ARM delay timer to be used for udelay(). This allows us to skip the delay loop calibration at boot on Marvell BG2, BG2Q, BG2CD platforms. And after this patch, udelay() will be unaffected by CPU frequency changes. Signed-off-by: Jisheng Z

Re: [PATCH] clocksource: dw_apb_timer_of: support timer-based delay

2015-10-30 Thread Jisheng Zhang
Dear Daniel, On Fri, 30 Oct 2015 16:27:39 +0800 Jisheng Zhang wrote: > Implement an ARM delay timer to be used for udelay(). This allows us to > skip the delay loop calibration at boot on Marvell BG2, BG2Q, BG2CD > platforms. And after this patch, udelay() will be unaffected by CPU > frequency c

[PATCH] clocksource: dw_apb_timer_of: support timer-based delay

2015-10-30 Thread Jisheng Zhang
Implement an ARM delay timer to be used for udelay(). This allows us to skip the delay loop calibration at boot on Marvell BG2, BG2Q, BG2CD platforms. And after this patch, udelay() will be unaffected by CPU frequency changes. Signed-off-by: Jisheng Zhang --- drivers/clocksource/Kconfig

Re: [RFC PATCH] clocksource: dw_apb_timer_of: support timer-based delay

2015-10-26 Thread Daniel Lezcano
On 10/20/2015 10:11 AM, Jisheng Zhang wrote: Implement an ARM delay timer to be used for udelay(). This allows us to skip the delay loop calibration at boot on Marvell BG2, BG2Q, BG2CD platforms. And after this patch, udelay() will be unaffected by CPU frequency changes. But, this driver is not

[RFC PATCH] clocksource: dw_apb_timer_of: support timer-based delay

2015-10-20 Thread Jisheng Zhang
Implement an ARM delay timer to be used for udelay(). This allows us to skip the delay loop calibration at boot on Marvell BG2, BG2Q, BG2CD platforms. And after this patch, udelay() will be unaffected by CPU frequency changes. But, this driver is not only used on ARM platforms, so I dunno how to h