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Commit d07bdd52 authored by Marek Vasut's avatar Marek Vasut Committed by Greg Kroah-Hartman
Browse files

i2c: xiic: Defer xiic_wakeup() and __xiic_start_xfer() in xiic_process() 



[ Upstream commit 743e227a895923c37a333eb2ebf3e391f00c406d ]

The __xiic_start_xfer() manipulates the interrupt flags, xiic_wakeup()
may result in return from xiic_xfer() early. Defer both to the end of
the xiic_process() interrupt thread, so that they are executed after
all the other interrupt bits handling completed and once it completely
safe to perform changes to the interrupt bits in the hardware.

Signed-off-by: default avatarMarek Vasut <marex@denx.de>
Acked-by: default avatarMichal Simek <michal.simek@xilinx.com>
Signed-off-by: default avatarWolfram Sang <wsa@kernel.org>
Stable-dep-of: cb6e45c9a0ad ("i2c: xiic: Don't try to handle more interrupt events after error")
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 479380ac

drivers/i2c/busses/i2c-xiic.c

+26 −11
Original line number Diff line number Diff line
@@ -362,6 +362,9 @@ static irqreturn_t xiic_process(int irq, void *dev_id) 
	struct xiic_i2c *i2c = dev_id;

	u32 pend, isr, ier;

	u32 clr = 0;

	int xfer_more = 0;

	int wakeup_req = 0;

	int wakeup_code = 0;



	/* Get the interrupt Status from the IPIF. There is no clearing of

	 * interrupts in the IPIF. Interrupts must be cleared at the source.
@@ -398,10 +401,14 @@ static irqreturn_t xiic_process(int irq, void *dev_id) 
		 */

		xiic_reinit(i2c);



		if (i2c->rx_msg)

			xiic_wakeup(i2c, STATE_ERROR);

		if (i2c->tx_msg)

			xiic_wakeup(i2c, STATE_ERROR);

		if (i2c->rx_msg) {

			wakeup_req = 1;

			wakeup_code = STATE_ERROR;

		}

		if (i2c->tx_msg) {

			wakeup_req = 1;

			wakeup_code = STATE_ERROR;

		}

	}

	if (pend & XIIC_INTR_RX_FULL_MASK) {

		/* Receive register/FIFO is full */
@@ -435,8 +442,7 @@ static irqreturn_t xiic_process(int irq, void *dev_id) 
				i2c->tx_msg++;

				dev_dbg(i2c->adap.dev.parent,

					"%s will start next...\n", __func__);



				__xiic_start_xfer(i2c);

				xfer_more = 1;

			}

		}

	}
@@ -450,11 +456,13 @@ static irqreturn_t xiic_process(int irq, void *dev_id) 
		if (!i2c->tx_msg)

			goto out;



		if ((i2c->nmsgs == 1) && !i2c->rx_msg &&

		wakeup_req = 1;



		if (i2c->nmsgs == 1 && !i2c->rx_msg &&

		    xiic_tx_space(i2c) == 0)

			xiic_wakeup(i2c, STATE_DONE);

			wakeup_code = STATE_DONE;

		else

			xiic_wakeup(i2c, STATE_ERROR);

			wakeup_code = STATE_ERROR;

	}

	if (pend & (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)) {

		/* Transmit register/FIFO is empty or ½ empty */
@@ -478,7 +486,7 @@ static irqreturn_t xiic_process(int irq, void *dev_id) 
			if (i2c->nmsgs > 1) {

				i2c->nmsgs--;

				i2c->tx_msg++;

				__xiic_start_xfer(i2c);

				xfer_more = 1;

			} else {

				xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK);
@@ -496,6 +504,13 @@ static irqreturn_t xiic_process(int irq, void *dev_id) 
	dev_dbg(i2c->adap.dev.parent, "%s clr: 0x%x\n", __func__, clr);



	xiic_setreg32(i2c, XIIC_IISR_OFFSET, clr);

	if (xfer_more)

		__xiic_start_xfer(i2c);

	if (wakeup_req)

		xiic_wakeup(i2c, wakeup_code);



	WARN_ON(xfer_more && wakeup_req);



	mutex_unlock(&i2c->lock);

	return IRQ_HANDLED;

}