@@ -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);
@@ -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)
@@ -752,6 +733,16 @@ 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;
@@ -893,19 +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);
This reverts commit 0317e6c0f1dc1ba86b8d9dccc010c5e77b8355fa. Srinivas reported recently touchscreen and touchpad stopped working in Haswell based machine in Linux 4.9-rc series with timeout errors from i2c_designware: [ 16.508013] i2c_designware INT33C3:00: controller timed out [ 16.508302] i2c_hid i2c-MSFT0001:02: failed to change power setting. [ 17.532016] i2c_designware INT33C3:00: controller timed out [ 18.556022] i2c_designware INT33C3:00: controller timed out [ 18.556315] i2c_hid i2c-ATML1000:00: failed to retrieve report from device. I managed to reproduce similar errors on another Haswell based machine where touchscreen initialization fails maybe in every 1/5 - 1/2 boots. Since root cause for these errors is not clear yet and debugging is ongoing it's better to revert this commit as we are near to release. Reported-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: Lucas De Marchi <lucas.demarchi@intel.com> Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> --- Also https://bugzilla.kernel.org/show_bug.cgi?id=188501 may relate to that but that's not confirmed yet with the reporter does revert help. --- drivers/i2c/busses/i2c-designware-core.c | 55 +++++++++++--------------------- 1 file changed, 18 insertions(+), 37 deletions(-)