From f36c1f9a8dfd6a78e6c3fe7aff5e722b84307597 Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Fri, 25 Jan 2019 07:29:20 +0000 Subject: [PATCH] i3c: master: dw: fix deadlock MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In dw_i3c_master_irq_handler(), we already have gotten &master->xferqueue.lock, if we try to get the same lock again in dw_i3c_master_dequeue_xfer(), deadlock happens. We fix this issue by introduing dw_i3c_master_dequeue_xfer_locked() which does all what dw_i3c_master_dequeue_xfer() does without trying to lock &master->xferqueue.lock. Signed-off-by: Jisheng Zhang Acked-by: Vitor Soares  Signed-off-by: Boris Brezillon --- drivers/i3c/master/dw-i3c-master.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c index f8c00b94817f..bb03079fbade 100644 --- a/drivers/i3c/master/dw-i3c-master.c +++ b/drivers/i3c/master/dw-i3c-master.c @@ -419,12 +419,9 @@ static void dw_i3c_master_enqueue_xfer(struct dw_i3c_master *master, spin_unlock_irqrestore(&master->xferqueue.lock, flags); } -static void dw_i3c_master_dequeue_xfer(struct dw_i3c_master *master, - struct dw_i3c_xfer *xfer) +static void dw_i3c_master_dequeue_xfer_locked(struct dw_i3c_master *master, + struct dw_i3c_xfer *xfer) { - unsigned long flags; - - spin_lock_irqsave(&master->xferqueue.lock, flags); if (master->xferqueue.cur == xfer) { u32 status; @@ -439,6 +436,15 @@ static void dw_i3c_master_dequeue_xfer(struct dw_i3c_master *master, } else { list_del_init(&xfer->node); } +} + +static void dw_i3c_master_dequeue_xfer(struct dw_i3c_master *master, + struct dw_i3c_xfer *xfer) +{ + unsigned long flags; + + spin_lock_irqsave(&master->xferqueue.lock, flags); + dw_i3c_master_dequeue_xfer_locked(master, xfer); spin_unlock_irqrestore(&master->xferqueue.lock, flags); } @@ -494,7 +500,7 @@ static void dw_i3c_master_end_xfer_locked(struct dw_i3c_master *master, u32 isr) complete(&xfer->comp); if (ret < 0) { - dw_i3c_master_dequeue_xfer(master, xfer); + dw_i3c_master_dequeue_xfer_locked(master, xfer); writel(readl(master->regs + DEVICE_CTRL) | DEV_CTRL_RESUME, master->regs + DEVICE_CTRL); }