Re: [PATCH V1 1/2] hw/rtc: Fixed loongson rtc emulation errors

[Bibo Mao]

On 2025/6/13 上午9:31, Xianglai Li wrote:

The expire time is sent to the timer only
when the expire Time is greater than 0 or
greater than now. Otherwise, the timer
will trigger interruption continuously.

Timer interrupts are sent using pulse functions.

Signed-off-by: Xianglai Li <lixiang...@loongson.cn>
---
Cc: Bibo Mao <maob...@loongson.cn>
Cc: Song Gao <gaos...@loongson.cn>
Cc: Jiaxun Yang <jiaxun.y...@flygoat.com>
Cc: Xianglai Li <lixiang...@loongson.cn>

  hw/loongarch/virt-fdt-build.c | 11 +++++++++--
  hw/rtc/ls7a_rtc.c             | 26 +++++++++++++++++---------
  2 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/hw/loongarch/virt-fdt-build.c b/hw/loongarch/virt-fdt-build.c
index 728ce46699..c613131a07 100644
--- a/hw/loongarch/virt-fdt-build.c
+++ b/hw/loongarch/virt-fdt-build.c
@@ -17,6 +17,11 @@
  #include "system/reset.h"
  #include "target/loongarch/cpu.h"

+#define FDT_IRQ_FLAGS_EDGE_LO_HI 1

+#define FDT_IRQ_FLAGS_EDGE_HI_LO 2
+#define FDT_IRQ_FLAGS_LEVEL_HI 4
+#define FDT_IRQ_FLAGS_LEVEL_LO 8
+
  static void create_fdt(LoongArchVirtMachineState *lvms)
  {
      MachineState *ms = MACHINE(lvms);
@@ -416,7 +421,8 @@ static void fdt_add_uart_node(LoongArchVirtMachineState 
*lvms,
      if (chosen) {
          qemu_fdt_setprop_string(ms->fdt, "/chosen", "stdout-path", nodename);
      }
-    qemu_fdt_setprop_cells(ms->fdt, nodename, "interrupts", irq, 0x4);
+    qemu_fdt_setprop_cells(ms->fdt, nodename, "interrupts", irq,
+                           FDT_IRQ_FLAGS_LEVEL_HI);
      qemu_fdt_setprop_cell(ms->fdt, nodename, "interrupt-parent",
                            *pch_pic_phandle);
      g_free(nodename);
@@ -436,7 +442,8 @@ static void fdt_add_rtc_node(LoongArchVirtMachineState 
*lvms,
                              "loongson,ls7a-rtc");
      qemu_fdt_setprop_sized_cells(ms->fdt, nodename, "reg", 2, base, 2, size);
      qemu_fdt_setprop_cells(ms->fdt, nodename, "interrupts",
-                           VIRT_RTC_IRQ - VIRT_GSI_BASE , 0x4);
+                           VIRT_RTC_IRQ - VIRT_GSI_BASE ,
+                           FDT_IRQ_FLAGS_EDGE_LO_HI);
      qemu_fdt_setprop_cell(ms->fdt, nodename, "interrupt-parent",
                            *pch_pic_phandle);
      g_free(nodename);
diff --git a/hw/rtc/ls7a_rtc.c b/hw/rtc/ls7a_rtc.c
index 10097b2db7..7eca75a42a 100644
--- a/hw/rtc/ls7a_rtc.c
+++ b/hw/rtc/ls7a_rtc.c
@@ -145,20 +145,24 @@ static void toymatch_write(LS7ARtcState *s, uint64_t val, 
int num)
          now = qemu_clock_get_ms(rtc_clock);
          toymatch_val_to_time(s, val, &tm);
          expire_time = now + (qemu_timedate_diff(&tm) - s->offset_toy) * 1000;
-        timer_mod(s->toy_timer[num], expire_time);
+        if (expire_time > now) {
+            timer_mod(s->toy_timer[num], expire_time);
+        }

Should rtc alarm interrupt be injected directly if (expire_time <= now)?

Regards
Bibo Mao

      }
  }

static void rtcmatch_write(LS7ARtcState *s, uint64_t val, int num)

  {
-    uint64_t expire_ns;
+    int64_t expire_ns;

/* it do not support write when toy disabled */

      if (rtc_enabled(s)) {
          s->rtcmatch[num] = val;
          /* calculate expire time */
          expire_ns = ticks_to_ns(val) - ticks_to_ns(s->offset_rtc);
-        timer_mod_ns(s->rtc_timer[num], expire_ns);
+        if (expire_ns > 0) {
+            timer_mod_ns(s->rtc_timer[num], expire_ns);
+        }
      }
  }

@@ -185,7 +189,7 @@ static void ls7a_rtc_stop(LS7ARtcState *s)

  static void ls7a_toy_start(LS7ARtcState *s)
  {
      int i;
-    uint64_t expire_time, now;
+    int64_t expire_time, now;
      struct tm tm = {};

now = qemu_clock_get_ms(rtc_clock);

@@ -194,19 +198,23 @@ static void ls7a_toy_start(LS7ARtcState *s)
      for (i = 0; i < TIMER_NUMS; i++) {
          toymatch_val_to_time(s, s->toymatch[i], &tm);
          expire_time = now + (qemu_timedate_diff(&tm) - s->offset_toy) * 1000;
-        timer_mod(s->toy_timer[i], expire_time);
+        if (expire_time > now) {
+            timer_mod(s->toy_timer[i], expire_time);
+        }
      }
  }

static void ls7a_rtc_start(LS7ARtcState *s)

  {
      int i;
-    uint64_t expire_time;
+    int64_t expire_time;

/* recalculate expire time and enable timer */

      for (i = 0; i < TIMER_NUMS; i++) {
          expire_time = ticks_to_ns(s->rtcmatch[i]) - 
ticks_to_ns(s->offset_rtc);
-        timer_mod_ns(s->rtc_timer[i], expire_time);
+        if (expire_time > 0) {
+            timer_mod_ns(s->rtc_timer[i], expire_time);
+        }
      }
  }

@@ -370,7 +378,7 @@ static void toy_timer_cb(void *opaque)

      LS7ARtcState *s = opaque;

if (toy_enabled(s)) {

-        qemu_irq_raise(s->irq);
+        qemu_irq_pulse(s->irq);
      }
  }

@@ -379,7 +387,7 @@ static void rtc_timer_cb(void *opaque)

      LS7ARtcState *s = opaque;

if (rtc_enabled(s)) {

-        qemu_irq_raise(s->irq);
+        qemu_irq_pulse(s->irq);
      }
  }