Hi Mark,

On 19 November 2016 at 03:56, Mark Rutland [off-list ref] wrote:

On Wed, Nov 16, 2016 at 09:49:01PM +0800, fu.wei at linaro.org wrote:

quoted

From: Fu Wei <redacted>

The patch refactor original arch_timer_needs_probing function:
    (1) Separate out arch_timer_needs_probing from arch_timer_common_init,
    and call it only if acpi disabled.
    (2) Rename arch_timer_needs_probing to arch_timer_needs_of_probing.

Please write a real commit message.

OK, how about this:

clocksource/drivers/arm_arch_timer: Refactor
arch_timer_needs_probing, only use it in the DT init code

Currently, the arch_timer_common_init uses arch_timer_needs_probing call to
wait for both timers been probed which is only for booting from DT.

For booting from ACPI, we don't need these in arch_timer_common_init, these code
should be only in the DT init code.

This patch seperates arch_timer_needs_probing related code out into a
new function
named arch_timer_needs_of_probing, and then reworks arch_timer_of_init
to use it,
so that we can keep this only in the DT init code.

quoted

Signed-off-by: Fu Wei <redacted>
---
 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 fe4e812..9ddc091 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c

@@ -792,15 +792,28 @@ 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;
+
+     /* 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);

-     dn = of_find_matching_node(NULL, matches);
-     if (dn && of_device_is_available(dn) && !(arch_timers_present & type))
+     if (dn && of_device_is_available(dn))
              needs_probing = true;
+
      of_node_put(dn);

      return needs_probing;

@@ -808,17 +821,8 @@ arch_timer_needs_probing(int type, const struct of_device_id *matches)

 static int __init arch_timer_common_init(void)
 {
-     unsigned int 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;
-     }

Why can't we just move this into the DT-specific caller of
arch_timer_common_init()?

yes, I have thought about this, but that means we have to split arch_timer_init,
and use arch_timer_register and arch_timer_common_init directly in
arch_timer_of_init.

In another word, I also need to modify arch_timer_of_init, not only
arch_timer_common_init,
but let me have a try in v17, see if you like it.

Thanks
Mark.

quoted

+     if (acpi_disabled && arch_timer_needs_of_probing())
+             return 0;

      arch_timer_banner(arch_timers_present);
      arch_counter_register(arch_timers_present);
--
2.7.4

-- 
Best regards,

Fu Wei
Software Engineer
Red Hat