From a44fe13eab664ac488ced0845d9885b019bd24c5 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Fri, 30 Sep 2005 08:25:17 +1000 Subject: [PATCH] [PATCH] Fix ppc64 smu driver locking The SMU driver has a small mistake in the locking of the interrupt code, if polled access and interrupt access race, interrupt may take a lock and return without releasing it. This fixes it. With that patch, the driver is rock solid with my experimental thermal control (which bangs it pretty hard) racing with real time clock and cpufreq handling. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Linus Torvalds --- drivers/macintosh/smu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c index a85ac18dd21..9b38674fbf7 100644 --- a/drivers/macintosh/smu.c +++ b/drivers/macintosh/smu.c @@ -153,8 +153,10 @@ static irqreturn_t smu_db_intr(int irq, void *arg, struct pt_regs *regs) spin_lock_irqsave(&smu->lock, flags); gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell); - if ((gpio & 7) != 7) + if ((gpio & 7) != 7) { + spin_unlock_irqrestore(&smu->lock, flags); return IRQ_HANDLED; + } cmd = smu->cmd_cur; smu->cmd_cur = NULL; -- 2.20.1