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@xxxxxxxxxxxxxxx> Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxx> Signed-off-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx> --- 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(-) diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index c53058d6139c..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); @@ -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); -- 2.10.2 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
