On 2017/1/19 17:44, Fu Wei wrote:
Hi Hanjun,
On 19 January 2017 at 16:02, Hanjun Guo <hanjun.guo@xxxxxxxxxx> wrote:
Hi Fuwei,
One comments below.
On 2017/1/18 21:25, fu.wei@xxxxxxxxxx wrote:
From: Fu Wei <fu.wei@xxxxxxxxxx>
The counter frequency detection call(arch_timer_detect_rate) combines two
ways to get counter frequency: system coprocessor register and MMIO timer.
But in a specific timer init code, we only need one way to try:
getting frequency from MMIO timer register will be needed only when we
init MMIO timer; getting frequency from system coprocessor register will
be needed only when we init arch timer.
This patch separates paths to determine frequency:
Separate out the MMIO frequency and the sysreg frequency detection call,
and use the appropriate one for the counter.
Signed-off-by: Fu Wei <fu.wei@xxxxxxxxxx>
---
drivers/clocksource/arm_arch_timer.c | 40
++++++++++++++++++++++--------------
1 file changed, 25 insertions(+), 15 deletions(-)
diff --git a/drivers/clocksource/arm_arch_timer.c
b/drivers/clocksource/arm_arch_timer.c
index 6484f84..9482481 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -488,23 +488,33 @@ static int arch_timer_starting_cpu(unsigned int cpu)
return 0;
}
-static void arch_timer_detect_rate(void __iomem *cntbase)
+static void __arch_timer_determine_rate(u32 rate)
{
- /* Who has more than one independent system counter? */
- if (arch_timer_rate)
- return;
+ /* Check the timer frequency. */
+ if (!arch_timer_rate) {
+ if (rate)
+ arch_timer_rate = rate;
+ else
+ pr_warn("frequency not available\n");
+ } else if (rate && arch_timer_rate != rate) {
^
Typo? I think it's "&" here.
Not a typo, It's definitely a “&&” :-)
Here arch_timer_rate is not zero.
If rate is not zero(that means we got a valid rate), and
arch_timer_rate != rate ,
we will print warning message.
Ah, misreading the code, thanks for clarify :)
Hanjun
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