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

Pull i2c fixes from Wolfram Sang:
 "Three driver bugfixes, and two reverts because the original patches
  revealed underlying problems which the Tegra guys are now working on"

* 'i2c/for-current-fixed' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: aspeed: Avoid i2c interrupt status clear race condition.
  i2c: amd-mp2-pci: Fix Oops in amd_mp2_pci_init() error handling
  Revert "i2c: tegra: Better handle case where CPU0 is busy for a long time"
  Revert "i2c: tegra: Synchronize DMA before termination"
  i2c: iproc: generate stop event for slave writes

Author: torvalds

drivers/i2c/busses/i2c-amd-mp2-pci.c

@@ -349,12 +349,12 @@ static int amd_mp2_pci_probe(struct pci_dev *pci_dev,
 	if (!privdata)
 		return -ENOMEM;
 
+	privdata->pci_dev = pci_dev;
 	rc = amd_mp2_pci_init(privdata, pci_dev);
 	if (rc)
 		return rc;
 
 	mutex_init(&privdata->c2p_lock);
-	privdata->pci_dev = pci_dev;
 
 	pm_runtime_set_autosuspend_delay(&pci_dev->dev, 1000);
 	pm_runtime_use_autosuspend(&pci_dev->dev);

drivers/i2c/busses/i2c-aspeed.c

@@ -603,6 +603,7 @@ static irqreturn_t aspeed_i2c_bus_irq(int irq, void *dev_id)
 	/* Ack all interrupts except for Rx done */
 	writel(irq_received & ~ASPEED_I2CD_INTR_RX_DONE,
 	       bus->base + ASPEED_I2C_INTR_STS_REG);
+	readl(bus->base + ASPEED_I2C_INTR_STS_REG);
 	irq_remaining = irq_received;
 
 #if IS_ENABLED(CONFIG_I2C_SLAVE)
@@ -645,9 +646,11 @@ static irqreturn_t aspeed_i2c_bus_irq(int irq, void *dev_id)
 			irq_received, irq_handled);
 
 	/* Ack Rx done */
-	if (irq_received & ASPEED_I2CD_INTR_RX_DONE)
+	if (irq_received & ASPEED_I2CD_INTR_RX_DONE) {
 		writel(ASPEED_I2CD_INTR_RX_DONE,
 		       bus->base + ASPEED_I2C_INTR_STS_REG);
+		readl(bus->base + ASPEED_I2C_INTR_STS_REG);
+	}
 	spin_unlock(&bus->lock);
 	return irq_remaining ? IRQ_NONE : IRQ_HANDLED;
 }

drivers/i2c/busses/i2c-bcm-iproc.c

@@ -360,6 +360,9 @@ static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c,
 			value = (u8)((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK);
 			i2c_slave_event(iproc_i2c->slave,
 					I2C_SLAVE_WRITE_RECEIVED, &value);
+			if (rx_status == I2C_SLAVE_RX_END)
+				i2c_slave_event(iproc_i2c->slave,
+						I2C_SLAVE_STOP, &value);
 		}
 	} else if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) {
 		/* Master read other than start */

drivers/i2c/busses/i2c-tegra.c

@@ -996,13 +996,14 @@ tegra_i2c_poll_completion_timeout(struct tegra_i2c_dev *i2c_dev,
 	do {
 		u32 status = i2c_readl(i2c_dev, I2C_INT_STATUS);
 
-		if (status)
+		if (status) {
 			tegra_i2c_isr(i2c_dev->irq, i2c_dev);
 
-		if (completion_done(complete)) {
-			s64 delta = ktime_ms_delta(ktimeout, ktime);
+			if (completion_done(complete)) {
+				s64 delta = ktime_ms_delta(ktimeout, ktime);
 
-			return msecs_to_jiffies(delta) ?: 1;
+				return msecs_to_jiffies(delta) ?: 1;
+			}
 		}
 
 		ktime = ktime_get();
@@ -1029,18 +1030,14 @@ tegra_i2c_wait_completion_timeout(struct tegra_i2c_dev *i2c_dev,
 		disable_irq(i2c_dev->irq);
 
 		/*
-		 * Under some rare circumstances (like running KASAN +
-		 * NFS root) CPU, which handles interrupt, may stuck in
-		 * uninterruptible state for a significant time.  In this
-		 * case we will get timeout if I2C transfer is running on
-		 * a sibling CPU, despite of IRQ being raised.
-		 *
-		 * In order to handle this rare condition, the IRQ status
-		 * needs to be checked after timeout.
+		 * There is a chance that completion may happen after IRQ
+		 * synchronization, which is done by disable_irq().
 		 */
-		if (ret == 0)
-			ret = tegra_i2c_poll_completion_timeout(i2c_dev,
-								complete, 0);
+		if (ret == 0 && completion_done(complete)) {
+			dev_warn(i2c_dev->dev,
+				 "completion done after timeout\n");
+			ret = 1;
+		}
 	}
 
 	return ret;
@@ -1219,15 +1216,6 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
 		time_left = tegra_i2c_wait_completion_timeout(
 				i2c_dev, &i2c_dev->dma_complete, xfer_time);
 
-		/*
-		 * Synchronize DMA first, since dmaengine_terminate_sync()
-		 * performs synchronization after the transfer's termination
-		 * and we want to get a completion if transfer succeeded.
-		 */
-		dmaengine_synchronize(i2c_dev->msg_read ?
-				      i2c_dev->rx_dma_chan :
-				      i2c_dev->tx_dma_chan);
-
 		dmaengine_terminate_sync(i2c_dev->msg_read ?
 					 i2c_dev->rx_dma_chan :
 					 i2c_dev->tx_dma_chan);