Merge branch 'i2c/for-current-fixed' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c fixes from Wolfram Sang:
 "A few driver fixes for the I2C subsystem"

* 'i2c/for-current-fixed' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: stm32f7: remove warning when compiling with W=1
  i2c: stm32f7: fix a race in slave mode with arbitration loss irq
  i2c: stm32f7: fix first byte to send in slave mode
  i2c: mt65xx: fix NULL ptr dereference
  i2c: aspeed: fix master pending state handling

3 files changed, 48 insertions, 29 deletions

diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
index fa66951b05d0..7b098ff5f5dd 100644
--- a/drivers/i2c/busses/i2c-aspeed.c
+++ b/drivers/i2c/busses/i2c-aspeed.c
@@ -108,6 +108,12 @@
 #define ASPEED_I2CD_S_TX_CMD				BIT(2)
 #define ASPEED_I2CD_M_TX_CMD				BIT(1)
 #define ASPEED_I2CD_M_START_CMD				BIT(0)
+#define ASPEED_I2CD_MASTER_CMDS_MASK					       \
+		(ASPEED_I2CD_M_STOP_CMD |				       \
+		 ASPEED_I2CD_M_S_RX_CMD_LAST |				       \
+		 ASPEED_I2CD_M_RX_CMD |					       \
+		 ASPEED_I2CD_M_TX_CMD |					       \
+		 ASPEED_I2CD_M_START_CMD)
 
 /* 0x18 : I2CD Slave Device Address Register   */
 #define ASPEED_I2CD_DEV_ADDR_MASK			GENMASK(6, 0)
@@ -336,18 +342,19 @@ static void aspeed_i2c_do_start(struct aspeed_i2c_bus *bus)
 	struct i2c_msg *msg = &bus->msgs[bus->msgs_index];
 	u8 slave_addr = i2c_8bit_addr_from_msg(msg);
 
-	bus->master_state = ASPEED_I2C_MASTER_START;
-
 #if IS_ENABLED(CONFIG_I2C_SLAVE)
 	/*
 	 * If it's requested in the middle of a slave session, set the master
 	 * state to 'pending' then H/W will continue handling this master
 	 * command when the bus comes back to the idle state.
 	 */
-	if (bus->slave_state != ASPEED_I2C_SLAVE_INACTIVE)
+	if (bus->slave_state != ASPEED_I2C_SLAVE_INACTIVE) {
 		bus->master_state = ASPEED_I2C_MASTER_PENDING;
+		return;
+	}
 #endif /* CONFIG_I2C_SLAVE */
 
+	bus->master_state = ASPEED_I2C_MASTER_START;
 	bus->buf_index = 0;
 
 	if (msg->flags & I2C_M_RD) {
@@ -422,20 +429,6 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status)
 		}
 	}
 
-#if IS_ENABLED(CONFIG_I2C_SLAVE)
-	/*
-	 * A pending master command will be started by H/W when the bus comes
-	 * back to idle state after completing a slave operation so change the
-	 * master state from 'pending' to 'start' at here if slave is inactive.
-	 */
-	if (bus->master_state == ASPEED_I2C_MASTER_PENDING) {
-		if (bus->slave_state != ASPEED_I2C_SLAVE_INACTIVE)
-			goto out_no_complete;
-
-		bus->master_state = ASPEED_I2C_MASTER_START;
-	}
-#endif /* CONFIG_I2C_SLAVE */
-
 	/* Master is not currently active, irq was for someone else. */
 	if (bus->master_state == ASPEED_I2C_MASTER_INACTIVE ||
 	    bus->master_state == ASPEED_I2C_MASTER_PENDING)
@@ -462,11 +455,15 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status)
 #if IS_ENABLED(CONFIG_I2C_SLAVE)
 		/*
 		 * If a peer master starts a xfer immediately after it queues a
-		 * master command, change its state to 'pending' then H/W will
-		 * continue the queued master xfer just after completing the
-		 * slave mode session.
+		 * master command, clear the queued master command and change
+		 * its state to 'pending'. To simplify handling of pending
+		 * cases, it uses S/W solution instead of H/W command queue
+		 * handling.
 		 */
 		if (unlikely(irq_status & ASPEED_I2CD_INTR_SLAVE_MATCH)) {
+			writel(readl(bus->base + ASPEED_I2C_CMD_REG) &
+				~ASPEED_I2CD_MASTER_CMDS_MASK,
+			       bus->base + ASPEED_I2C_CMD_REG);
 			bus->master_state = ASPEED_I2C_MASTER_PENDING;
 			dev_dbg(bus->dev,
 				"master goes pending due to a slave start\n");
@@ -629,6 +626,14 @@ static irqreturn_t aspeed_i2c_bus_irq(int irq, void *dev_id)
 			irq_handled |= aspeed_i2c_master_irq(bus,
 							     irq_remaining);
 	}
+
+	/*
+	 * Start a pending master command at here if a slave operation is
+	 * completed.
+	 */
+	if (bus->master_state == ASPEED_I2C_MASTER_PENDING &&
+	    bus->slave_state == ASPEED_I2C_SLAVE_INACTIVE)
+		aspeed_i2c_do_start(bus);
 #else
 	irq_handled = aspeed_i2c_master_irq(bus, irq_remaining);
 #endif /* CONFIG_I2C_SLAVE */
@@ -691,6 +696,15 @@ static int aspeed_i2c_master_xfer(struct i2c_adapter *adap,
 		     ASPEED_I2CD_BUS_BUSY_STS))
 			aspeed_i2c_recover_bus(bus);
 
+		/*
+		 * If timed out and the state is still pending, drop the pending
+		 * master command.
+		 */
+		spin_lock_irqsave(&bus->lock, flags);
+		if (bus->master_state == ASPEED_I2C_MASTER_PENDING)
+			bus->master_state = ASPEED_I2C_MASTER_INACTIVE;
+		spin_unlock_irqrestore(&bus->lock, flags);
+
 		return -ETIMEDOUT;
 	}
 
diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 29eae1bf4f86..2152ec5f535c 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -875,7 +875,7 @@ static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id)
 
 static u32 mtk_i2c_functionality(struct i2c_adapter *adap)
 {
-	if (adap->quirks->flags & I2C_AQ_NO_ZERO_LEN)
+	if (i2c_check_quirks(adap, I2C_AQ_NO_ZERO_LEN))
 		return I2C_FUNC_I2C |
 			(I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
 	else
diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index d36cf08461f7..b24e7b937f21 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -305,7 +305,7 @@ struct stm32f7_i2c_dev {
 	struct regmap *regmap;
 };
 
-/**
+/*
  * All these values are coming from I2C Specification, Version 6.0, 4th of
  * April 2014.
  *
@@ -1192,6 +1192,8 @@ static void stm32f7_i2c_slave_start(struct stm32f7_i2c_dev *i2c_dev)
 			STM32F7_I2C_CR1_TXIE;
 		stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
 
+		/* Write 1st data byte */
+		writel_relaxed(value, base + STM32F7_I2C_TXDR);
 	} else {
 		/* Notify i2c slave that new write transfer is starting */
 		i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
@@ -1501,7 +1503,7 @@ static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data)
 	void __iomem *base = i2c_dev->base;
 	struct device *dev = i2c_dev->dev;
 	struct stm32_i2c_dma *dma = i2c_dev->dma;
-	u32 mask, status;
+	u32 status;
 
 	status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
 
@@ -1526,12 +1528,15 @@ static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data)
 		f7_msg->result = -EINVAL;
 	}
 
-	/* Disable interrupts */
-	if (stm32f7_i2c_is_slave_registered(i2c_dev))
-		mask = STM32F7_I2C_XFER_IRQ_MASK;
-	else
-		mask = STM32F7_I2C_ALL_IRQ_MASK;
-	stm32f7_i2c_disable_irq(i2c_dev, mask);
+	if (!i2c_dev->slave_running) {
+		u32 mask;
+		/* Disable interrupts */
+		if (stm32f7_i2c_is_slave_registered(i2c_dev))
+			mask = STM32F7_I2C_XFER_IRQ_MASK;
+		else
+			mask = STM32F7_I2C_ALL_IRQ_MASK;
+		stm32f7_i2c_disable_irq(i2c_dev, mask);
+	}
 
 	/* Disable dma */
 	if (i2c_dev->use_dma) {