Commit f36c1f9a authored by Jisheng Zhang's avatar Jisheng Zhang Committed by Boris Brezillon
Browse files

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: default avatarJisheng Zhang <Jisheng.Zhang@synaptics.com>
Acked-by: default avatar < Vitor Soares &lt;vitor.soares@synopsys.com>
Signed-off-by: default avatarBoris Brezillon <bbrezillon@kernel.org>
parent 093c61b6

drivers/i3c/master/dw-i3c-master.c

+12 −6
Original line number Original line Diff line number Diff line
@@ -419,12 +419,9 @@ static void dw_i3c_master_enqueue_xfer(struct dw_i3c_master *master, 
	spin_unlock_irqrestore(&master->xferqueue.lock, flags);

	spin_unlock_irqrestore(&master->xferqueue.lock, flags);

}

}





static void dw_i3c_master_dequeue_xfer(struct dw_i3c_master *master,

static void dw_i3c_master_dequeue_xfer_locked(struct dw_i3c_master *master,

					      struct dw_i3c_xfer *xfer)

					      struct dw_i3c_xfer *xfer)

{

{

	unsigned long flags;



	spin_lock_irqsave(&master->xferqueue.lock, flags);

	if (master->xferqueue.cur == xfer) {

	if (master->xferqueue.cur == xfer) {

		u32 status;

		u32 status;
@@ -439,6 +436,15 @@ static void dw_i3c_master_dequeue_xfer(struct dw_i3c_master *master, 
	} else {

	} else {

		list_del_init(&xfer->node);

		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);

	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);

	complete(&xfer->comp);





	if (ret < 0) {

	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,

		writel(readl(master->regs + DEVICE_CTRL) | DEV_CTRL_RESUME,

		       master->regs + DEVICE_CTRL);

		       master->regs + DEVICE_CTRL);

	}

	}

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