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authorJisheng Zhang <Jisheng.Zhang@synaptics.com>2019-01-25 07:29:20 +0000
committerBoris Brezillon <bbrezillon@kernel.org>2019-01-26 11:14:25 +0100
commitf36c1f9a8dfd6a78e6c3fe7aff5e722b84307597 (patch)
treecf6b4f9bf5e9c4de75deb6d51a45088ee6b4faf0 /drivers/i3c
parent093c61b6a0d5768f48442ec59d671496314cc47d (diff)
downloadlinux-f36c1f9a8dfd6a78e6c3fe7aff5e722b84307597.tar.gz
i3c: master: dw: fix deadlock
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 <Jisheng.Zhang@synaptics.com> Acked-by: Vitor Soares <vitor.soares@synopsys.com> Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Diffstat (limited to 'drivers/i3c')
-rw-r--r--drivers/i3c/master/dw-i3c-master.c18
1 files 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);
}