From patchwork Sun May 2 09:50:51 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [1/2] arm_timer: reload timer when enabled Date: Sat, 01 May 2010 23:50:51 -0000 From: Rabin Vincent X-Patchwork-Id: 51462 Message-Id: <1272793852-26260-1-git-send-email-rabin@rab.in> To: qemu-devel@nongnu.org Cc: Rabin Vincent Reload the timer when TimerControl is written, if the timer is to be enabled. Otherwise, if an earlier write to TimerLoad was done while periodic mode was not set, s->delta may incorrectly still have the value of the maximum limit instead of the value written to TimerLoad. This problem is evident on versatileap on current linux-next, which enables TIMER_CTRL_32BIT before writing to TimerLoad and then enabling periodic mode and starting the timer. This causes the first periodic tick to be scheduled to occur after 0xffffffff periods, leading to a perceived hang while the kernel waits for the first timer tick. Signed-off-by: Rabin Vincent --- hw/arm_timer.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/hw/arm_timer.c b/hw/arm_timer.c index 9fef191..5b6947a 100644 --- a/hw/arm_timer.c +++ b/hw/arm_timer.c @@ -113,7 +113,7 @@ static void arm_timer_write(void *opaque, target_phys_addr_t offset, case 1: freq >>= 4; break; case 2: freq >>= 8; break; } - arm_timer_recalibrate(s, 0); + arm_timer_recalibrate(s, s->control & TIMER_CTRL_ENABLE); ptimer_set_freq(s->timer, freq); if (s->control & TIMER_CTRL_ENABLE) { /* Restart the timer if still enabled. */