lkml.org 
[lkml]   [2017]   [Mar]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v22 03/11] clocksource: arm_arch_timer: refactor arch_timer_needs_probing
On Wed, Mar 22, 2017 at 12:31:14AM +0800, fu.wei@linaro.org wrote:
> From: Fu Wei <fu.wei@linaro.org>
>
> When system init with device-tree, we don't know which node will be
> initialized first. And the code in arch_timer_common_init should wait
> until per-cpu timer and MMIO timer are both initialized. So we need
> arch_timer_needs_probing to detect the init status of system.
>
> But currently the code is dispersed in arch_timer_needs_probing and
> arch_timer_common_init. And the function name doesn't specify that
> it's only for device-tree. This is somewhat confusing.

Can the following patch help you to solve nicely the situation ?

https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1360007.html

> This patch move all related code from arch_timer_common_init to
> arch_timer_needs_probing, refactor it, and rename it to
> arch_timer_needs_of_probing. And make sure that it will be called
> only if acpi is disabled.
>
> Signed-off-by: Fu Wei <fu.wei@linaro.org>
> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
> ---
> drivers/clocksource/arm_arch_timer.c | 34 +++++++++++++++++++---------------
> 1 file changed, 19 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
> index 29ca7d6..d1a05d9 100644
> --- a/drivers/clocksource/arm_arch_timer.c
> +++ b/drivers/clocksource/arm_arch_timer.c
> @@ -839,15 +839,28 @@ static const struct of_device_id arch_timer_mem_of_match[] __initconst = {
> {},
> };
>
> -static bool __init
> -arch_timer_needs_probing(int type, const struct of_device_id *matches)
> +static bool __init arch_timer_needs_of_probing(void)
> {
> struct device_node *dn;
> bool needs_probing = false;
> + unsigned int mask = ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM;
>
> - dn = of_find_matching_node(NULL, matches);
> - if (dn && of_device_is_available(dn) && !(arch_timers_present & type))
> + /* We have two timers, and both device-tree nodes are probed. */
> + if ((arch_timers_present & mask) == mask)
> + return false;
> +
> + /*
> + * Only one type of timer is probed,
> + * check if we have another type of timer node in device-tree.
> + */
> + if (arch_timers_present & ARCH_TIMER_TYPE_CP15)
> + dn = of_find_matching_node(NULL, arch_timer_mem_of_match);
> + else
> + dn = of_find_matching_node(NULL, arch_timer_of_match);
> +
> + if (dn && of_device_is_available(dn))
> needs_probing = true;
> +
> of_node_put(dn);
>
> return needs_probing;
> @@ -855,17 +868,8 @@ arch_timer_needs_probing(int type, const struct of_device_id *matches)
>
> static int __init arch_timer_common_init(void)
> {
> - unsigned mask = ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM;
> -
> - /* Wait until both nodes are probed if we have two timers */
> - if ((arch_timers_present & mask) != mask) {
> - if (arch_timer_needs_probing(ARCH_TIMER_TYPE_MEM,
> - arch_timer_mem_of_match))
> - return 0;
> - if (arch_timer_needs_probing(ARCH_TIMER_TYPE_CP15,
> - arch_timer_of_match))
> - return 0;
> - }
> + if (acpi_disabled && arch_timer_needs_of_probing())
> + return 0;
>
> arch_timer_banner(arch_timers_present);
> arch_counter_register(arch_timers_present);
> --
> 2.9.3
>

--

<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog

\
 
 \ /
  Last update: 2017-03-28 17:04    [W:1.152 / U:0.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site