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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>
This commit is contained in:
Jisheng Zhang 2019-01-25 07:29:20 +00:00 committed by Boris Brezillon
parent 093c61b6a0
commit f36c1f9a8d
1 changed files with 12 additions and 6 deletions
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18
drivers/i3c/master/dw-i3c-master.c
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@ -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);
}