On 19/02/2019 10:00, Joseph Lo wrote:

On 2/18/19 5:39 PM, Daniel Lezcano wrote:

quoted

On 18/02/2019 10:01, Joseph Lo wrote:

quoted

On 2/15/19 11:14 PM, Daniel Lezcano wrote:

quoted

On 01/02/2019 17:16, Joseph Lo wrote:

quoted

Add support for the Tegra210 timer that runs at oscillator clock
(TMR10-TMR13). We need these timers to work as clock event device
and to
replace the ARMv8 architected timer due to it can't survive across the
power cycle of the CPU core or CPUPORESET signal. So it can't be a
wake-up
source when CPU suspends in power down state.

Also convert the original driver to use timer-of API.

Cc: Daniel Lezcano <redacted>
Cc: Thomas Gleixner <redacted>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Joseph Lo <redacted>
Acked-by: Thierry Reding <redacted>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
---
v6:
   * refine the timer defines
   * add ack tag from Jon.
v5:
   * add ack tag from Thierry
v4:
   * merge timer-tegra210.c in previous version into timer-tegra20.c
v3:
   * use timer-of API
v2:
   * add error clean-up code
---

[snip]

quoted

quoted

quoted

quoted

+    for_each_possible_cpu(cpu) {
+        struct timer_of *cpu_to;
+
+        cpu_to = per_cpu_ptr(&tegra_to, cpu);
+        cpu_to->of_base.base = timer_reg_base +
TIMER_BASE_FOR_CPU(cpu);
+        cpu_to->of_clk.rate = timer_of_rate(to);
+        cpu_to->clkevt.cpumask = cpumask_of(cpu);
+
+        cpu_to->clkevt.irq =
+            irq_of_parse_and_map(np, IRQ_IDX_FOR_CPU(cpu));
+        if (!cpu_to->clkevt.irq) {
+            pr_err("%s: can't map IRQ for CPU%d\n",
+                   __func__, cpu);
+            ret = -EINVAL;
+            goto out;
+        }
+
+        irq_set_status_flags(cpu_to->clkevt.irq, IRQ_NOAUTOEN);
+        ret = request_irq(cpu_to->clkevt.irq, tegra_timer_isr,
+                  IRQF_TIMER | IRQF_NOBALANCING,
+                  cpu_to->clkevt.name, &cpu_to->clkevt);
+        if (ret) {
+            pr_err("%s: cannot setup irq %d for CPU%d\n",
+                __func__, cpu_to->clkevt.irq, cpu);
+            ret = -EINVAL;
+            goto out_irq;
+        }
+    }

You should configure the timer in the tegra_timer_setup() function
instead of using this cpu loop.

I think I still need to leave 'irq_of_parse_and_map' and 'request_irq'
here. Is that ok?

Perhaps you can store the np pointer in the private data structure of
timer-of and let the timer_of API to retrieve the irq in the cpuhp
callbacks.

irq_of_parse_and_map will be called by timer-of.

I'm not sure irq_set_status_flags really operates on the irq because it
is called after request_irq.

I did some experiments today. The 'irq_of_parse_and_map', 'request_irq'
and 'setup_irq' are not able to run in the atomic section that
tegra_timer_setup would be triggered in.

Oh ... right

So I think I still need to leave the IRQ configuration code here in the
loop. Should I move others to 'tegra_timer_setup' or just keep as the
same in this patch?

For the moment, I suggest you keep it as it was initially.

A side note, not related to this comment but about the DYNIRQ flag.
Actually it is not needed because the timers are per-cpu.

Thanks

  -- Daniel


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