Hi Will,

On 25 July 2016 at 23:31, Will Deacon [off-list ref] wrote:

On Mon, Jul 25, 2016 at 11:27:02PM +0800, fu.wei at linaro.org wrote:

quoted

From: Fu Wei <redacted>

This patch simplify arch_counter_get_cntvct_mem function by
using readq to get 64-bit CNTVCT value instead of readl_relaxed.

Signed-off-by: Fu Wei <redacted>
---
 drivers/clocksource/arm_arch_timer.c | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index e6fd42d..483d2f9 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c

@@ -418,15 +418,7 @@ u32 arch_timer_get_rate(void)

 static u64 arch_counter_get_cntvct_mem(void)
 {
-     u32 vct_lo, vct_hi, tmp_hi;
-
-     do {
-             vct_hi = readl_relaxed(arch_counter_base + CNTVCT_HI);
-             vct_lo = readl_relaxed(arch_counter_base + CNTVCT_LO);
-             tmp_hi = readl_relaxed(arch_counter_base + CNTVCT_HI);
-     } while (vct_hi != tmp_hi);
-
-     return ((u64) vct_hi << 32) | vct_lo;
+     return readq(arch_counter_base + CNTVCT_LO);

Please drop this patch. It doesn't work.

I am OK to drop this, but could you let me know why it doesn't work?

I did get some problem on Foundation model about readq, but it works on Seattle.
I guess that is a problem of model, but not a code problem.
So I just got confused, why readq  doesn't work,  :-)

http://lists.infradead.org/pipermail/linux-arm-kernel/2016-July/445369.html

I just replied to it, sorry.

Will

-- 
Best regards,

Fu Wei
Software Engineer
Red Hat