Merge tag 'i2c-host-fixes-7.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux into i2c/for-current

i2c-fixes for v7.0-rc6

designware: fix resume-probe race causing NULL-deref in amdisp
imx: fix timeout on repeated reads and extra clock at end

Author: Wolfram Sang

drivers/i2c/busses/i2c-designware-amdisp.c

@@ -7,6 +7,7 @@
 
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
 #include <linux/soc/amd/isp4_misc.h>
 
@@ -76,22 +77,20 @@ static int amd_isp_dw_i2c_plat_probe(struct platform_device *pdev)
 
 	device_enable_async_suspend(&pdev->dev);
 
-	pm_runtime_enable(&pdev->dev);
-	pm_runtime_get_sync(&pdev->dev);
-
+	dev_pm_genpd_resume(&pdev->dev);
 	ret = i2c_dw_probe(isp_i2c_dev);
 	if (ret) {
 		dev_err_probe(&pdev->dev, ret, "i2c_dw_probe failed\n");
 		goto error_release_rpm;
 	}
-
-	pm_runtime_put_sync(&pdev->dev);
+	dev_pm_genpd_suspend(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
 
 	return 0;
 
 error_release_rpm:
 	amd_isp_dw_i2c_plat_pm_cleanup(isp_i2c_dev);
-	pm_runtime_put_sync(&pdev->dev);
 	return ret;
 }
 

drivers/i2c/busses/i2c-imx.c

@@ -1018,8 +1018,9 @@ static inline int i2c_imx_isr_read(struct imx_i2c_struct *i2c_imx)
 	return 0;
 }
 
-static inline void i2c_imx_isr_read_continue(struct imx_i2c_struct *i2c_imx)
+static inline enum imx_i2c_state i2c_imx_isr_read_continue(struct imx_i2c_struct *i2c_imx)
 {
+	enum imx_i2c_state next_state = IMX_I2C_STATE_READ_CONTINUE;
 	unsigned int temp;
 
 	if ((i2c_imx->msg->len - 1) == i2c_imx->msg_buf_idx) {
@@ -1033,25 +1034,28 @@ static inline void i2c_imx_isr_read_continue(struct imx_i2c_struct *i2c_imx)
 				i2c_imx->stopped =  1;
 			temp &= ~(I2CR_MSTA | I2CR_MTX);
 			imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
-		} else {
-			/*
-			 * For i2c master receiver repeat restart operation like:
-			 * read -> repeat MSTA -> read/write
-			 * The controller must set MTX before read the last byte in
-			 * the first read operation, otherwise the first read cost
-			 * one extra clock cycle.
-			 */
-			temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
-			temp |= I2CR_MTX;
-			imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+			return IMX_I2C_STATE_DONE;
 		}
+		/*
+		 * For i2c master receiver repeat restart operation like:
+		 * read -> repeat MSTA -> read/write
+		 * The controller must set MTX before read the last byte in
+		 * the first read operation, otherwise the first read cost
+		 * one extra clock cycle.
+		 */
+		temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+		temp |= I2CR_MTX;
+		imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+		next_state = IMX_I2C_STATE_DONE;
 	} else if (i2c_imx->msg_buf_idx == (i2c_imx->msg->len - 2)) {
 		temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
 		temp |= I2CR_TXAK;
 		imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 	}
 
 	i2c_imx->msg->buf[i2c_imx->msg_buf_idx++] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
+	return next_state;
 }
 
 static inline void i2c_imx_isr_read_block_data_len(struct imx_i2c_struct *i2c_imx)
@@ -1088,11 +1092,9 @@ static irqreturn_t i2c_imx_master_isr(struct imx_i2c_struct *i2c_imx, unsigned i
 		break;
 
 	case IMX_I2C_STATE_READ_CONTINUE:
-		i2c_imx_isr_read_continue(i2c_imx);
-		if (i2c_imx->msg_buf_idx == i2c_imx->msg->len) {
-			i2c_imx->state = IMX_I2C_STATE_DONE;
+		i2c_imx->state = i2c_imx_isr_read_continue(i2c_imx);
+		if (i2c_imx->state == IMX_I2C_STATE_DONE)
 			wake_up(&i2c_imx->queue);
-		}
 		break;
 
 	case IMX_I2C_STATE_READ_BLOCK_DATA:
@@ -1490,6 +1492,7 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs,
 			bool is_lastmsg)
 {
 	int block_data = msgs->flags & I2C_M_RECV_LEN;
+	int ret = 0;
 
 	dev_dbg(&i2c_imx->adapter.dev,
 		"<%s> write slave address: addr=0x%x\n",
@@ -1522,10 +1525,20 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs,
 		dev_err(&i2c_imx->adapter.dev, "<%s> read timedout\n", __func__);
 		return -ETIMEDOUT;
 	}
-	if (!i2c_imx->stopped)
-		return i2c_imx_bus_busy(i2c_imx, 0, false);
+	if (i2c_imx->is_lastmsg) {
+		if (!i2c_imx->stopped)
+			ret = i2c_imx_bus_busy(i2c_imx, 0, false);
+		/*
+		 * Only read the last byte of the last message after the bus is
+		 * not busy. Else the controller generates another clock which
+		 * might confuse devices.
+		 */
+		if (!ret)
+			i2c_imx->msg->buf[i2c_imx->msg_buf_idx++] = imx_i2c_read_reg(i2c_imx,
+										     IMX_I2C_I2DR);
+	}
 
-	return 0;
+	return ret;
 }
 
 static int i2c_imx_xfer_common(struct i2c_adapter *adapter,