[Qemu-devel] [PATCH v1 3/3] armv7m_systick: abort instead of locking on a bad rate

From: KONRAD Frederic <frederic.konrad@adacore.com>
To: qemu-devel@nongnu.org
Cc: peter.maydell@linaro.org, alex.bennee@linaro.org,
	pbonzini@redhat.com, alistair@alistair23.me,
	frederic.konrad@adacore.com
Subject: [Qemu-devel] [PATCH v1 3/3] armv7m_systick: abort instead of locking on a bad rate
Date: Thu, 29 Jun 2017 11:28:53 +0200	[thread overview]
Message-ID: <1498728533-23160-4-git-send-email-frederic.konrad@adacore.com> (raw)
In-Reply-To: <1498728533-23160-1-git-send-email-frederic.konrad@adacore.com>

This helps the board developer by asserting that system_clock_rate is not
null. Using systick with a zero rate will lead to a deadlock so better showing
the error.

Signed-off-by: KONRAD Frederic <frederic.konrad@adacore.com>
---
 hw/timer/armv7m_systick.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hw/timer/armv7m_systick.c b/hw/timer/armv7m_systick.c
index df8d280..745efb7 100644
--- a/hw/timer/armv7m_systick.c
+++ b/hw/timer/armv7m_systick.c
@@ -54,6 +54,9 @@ static void systick_reload(SysTickState *s, int reset)
         s->tick = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
     }
     s->tick += (s->reload + 1) * systick_scale(s);
+
+    /* system_clock_scale = 0 leads to a nasty deadlock, better aborting */
+    assert(systick_scale(s));
     timer_mod(s->timer, s->tick);
 }
 
-- 
1.8.3.1
