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authorLinus Torvalds <torvalds@linux-foundation.org>2016-11-26 15:28:34 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-11-26 15:28:34 -0800
commite348031214d5dce67be93271433b27a93cba5b3f (patch)
treed8c9a8d61ef041a8a6629b34a6f2ebc19264d410
parenta56f3eb2cd72d4d678a63cf8cacf9d39aa8020f3 (diff)
parent89119f08354b628548118cacd686a7700372ad19 (diff)
downloadlinux-e348031214d5dce67be93271433b27a93cba5b3f.tar.bz2
Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c fixes from Wolfram Sang: "Here is a revert and two bugfixes for the I2C designware driver. Please note that we are still hunting down a regression for the i2c-octeon driver. While there is a fix pending, we have unclear feedback from the testers currently. An rc8 would be quite helpful for this case" * 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: Revert "i2c: designware: do not disable adapter after transfer" i2c: designware: fix rx fifo depth tracking i2c: designware: report short transfers
-rw-r--r--drivers/i2c/busses/i2c-designware-core.c64
1 files changed, 25 insertions, 39 deletions
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index 11e866d05368..b403fa5ecf49 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -91,9 +91,7 @@
DW_IC_INTR_TX_ABRT | \
DW_IC_INTR_STOP_DET)
-#define DW_IC_STATUS_ACTIVITY 0x1
-#define DW_IC_STATUS_TFE BIT(2)
-#define DW_IC_STATUS_MST_ACTIVITY BIT(5)
+#define DW_IC_STATUS_ACTIVITY 0x1
#define DW_IC_SDA_HOLD_RX_SHIFT 16
#define DW_IC_SDA_HOLD_RX_MASK GENMASK(23, DW_IC_SDA_HOLD_RX_SHIFT)
@@ -478,25 +476,9 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
{
struct i2c_msg *msgs = dev->msgs;
u32 ic_tar = 0;
- bool enabled;
- enabled = dw_readl(dev, DW_IC_ENABLE_STATUS) & 1;
-
- if (enabled) {
- u32 ic_status;
-
- /*
- * Only disable adapter if ic_tar and ic_con can't be
- * dynamically updated
- */
- ic_status = dw_readl(dev, DW_IC_STATUS);
- if (!dev->dynamic_tar_update_enabled ||
- (ic_status & DW_IC_STATUS_MST_ACTIVITY) ||
- !(ic_status & DW_IC_STATUS_TFE)) {
- __i2c_dw_enable_and_wait(dev, false);
- enabled = false;
- }
- }
+ /* Disable the adapter */
+ __i2c_dw_enable_and_wait(dev, false);
/* if the slave address is ten bit address, enable 10BITADDR */
if (dev->dynamic_tar_update_enabled) {
@@ -526,8 +508,8 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
/* enforce disabled interrupts (due to HW issues) */
i2c_dw_disable_int(dev);
- if (!enabled)
- __i2c_dw_enable(dev, true);
+ /* Enable the adapter */
+ __i2c_dw_enable(dev, true);
/* Clear and enable interrupts */
dw_readl(dev, DW_IC_CLR_INTR);
@@ -611,7 +593,7 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
/* avoid rx buffer overrun */
- if (rx_limit - dev->rx_outstanding <= 0)
+ if (dev->rx_outstanding >= dev->rx_fifo_depth)
break;
dw_writel(dev, cmd | 0x100, DW_IC_DATA_CMD);
@@ -708,8 +690,7 @@ static int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev)
}
/*
- * Prepare controller for a transaction and start transfer by calling
- * i2c_dw_xfer_init()
+ * Prepare controller for a transaction and call i2c_dw_xfer_msg
*/
static int
i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
@@ -752,13 +733,23 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
goto done;
}
+ /*
+ * We must disable the adapter before returning and signaling the end
+ * of the current transfer. Otherwise the hardware might continue
+ * generating interrupts which in turn causes a race condition with
+ * the following transfer. Needs some more investigation if the
+ * additional interrupts are a hardware bug or this driver doesn't
+ * handle them correctly yet.
+ */
+ __i2c_dw_enable(dev, false);
+
if (dev->msg_err) {
ret = dev->msg_err;
goto done;
}
/* no error */
- if (likely(!dev->cmd_err)) {
+ if (likely(!dev->cmd_err && !dev->status)) {
ret = num;
goto done;
}
@@ -768,6 +759,11 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
ret = i2c_dw_handle_tx_abort(dev);
goto done;
}
+
+ if (dev->status)
+ dev_err(dev->dev,
+ "transfer terminated early - interrupt latency too high?\n");
+
ret = -EIO;
done:
@@ -888,19 +884,9 @@ static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
*/
tx_aborted:
- if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET))
- || dev->msg_err) {
- /*
- * We must disable interruts before returning and signaling
- * the end of the current transfer. Otherwise the hardware
- * might continue generating interrupts for non-existent
- * transfers.
- */
- i2c_dw_disable_int(dev);
- dw_readl(dev, DW_IC_CLR_INTR);
-
+ if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err)
complete(&dev->cmd_complete);
- } else if (unlikely(dev->accessor_flags & ACCESS_INTR_MASK)) {
+ else if (unlikely(dev->accessor_flags & ACCESS_INTR_MASK)) {
/* workaround to trigger pending interrupt */
stat = dw_readl(dev, DW_IC_INTR_MASK);
i2c_dw_disable_int(dev);