From bdd1741cf18959e70cdfc6f46bb41d9209e86315 Mon Sep 17 00:00:00 2001
From: jianchunfu <jianchunfu_yewu@cmss.chinamobile.com>
Date: Thu, 24 Nov 2022 17:18:00 +0800
Subject: [PATCH 18/29] target/imx: reload cmp timer outside of the reload
 ptimer transaction

When running seL4 tests (https://docs.sel4.systems/projects/sel4test)
on the sabrelight platform, the timer tests fail. The arm/imx6 EPIT
timer interrupt does not fire properly, instead of a e.g. second in
can take up to a minute to finally see the interrupt.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1263

Signed-off-by: Axel Heider <axel.heider@hensoldt.net>
Signed-off-by: jianchunfu <jianchunfu_yewu@cmss.chinamobile.com>
---
 hw/timer/imx_epit.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/hw/timer/imx_epit.c b/hw/timer/imx_epit.c
index ebd58254d1..a78b625d15 100644
--- a/hw/timer/imx_epit.c
+++ b/hw/timer/imx_epit.c
@@ -275,10 +275,15 @@ static void imx_epit_write(void *opaque, hwaddr offset, uint64_t value,
             /* If IOVW bit is set then set the timer value */
             ptimer_set_count(s->timer_reload, s->lr);
         }
-
+        /*
+         * Commit the change to s->timer_reload, so it can propagate. Otherwise
+         * the timer interrupt may not fire properly. The commit must happen
+         * before calling imx_epit_reload_compare_timer(), which reads
+         * s->timer_reload internally again.
+         */
+        ptimer_transaction_commit(s->timer_reload);
         imx_epit_reload_compare_timer(s);
         ptimer_transaction_commit(s->timer_cmp);
-        ptimer_transaction_commit(s->timer_reload);
         break;
 
     case 3: /* CMP */
-- 
2.27.0