From 2b84a4dd4be0fd6d6fecdb14040cbbc38a3b525a Mon Sep 17 00:00:00 2001 From: Abhishek Sahu Date: Mon, 9 May 2016 18:14:30 +0530 Subject: [PATCH] i2c: qup: Cleared the error bits in ISR 1. Current QCOM I2C driver hangs when sending data to address 0x03-0x07 in some scenarios. The QUP controller generates invalid write in this case, since these addresses are reserved for different bus formats. 2. Also, the error handling is done by I2C QUP ISR in the case of DMA mode. The state need to be RESET in case of any error for clearing the available data in FIFO, which otherwise leaves the BAM DMA controller in hang state. This patch fixes the above two issues by clearing the error bits from I2C and QUP status in ISR in case of I2C error, QUP error and resets the QUP state to clear the FIFO data. Signed-off-by: Abhishek Sahu Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-qup.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c index 69849a95d479..686f262e34f7 100644 --- a/drivers/i2c/busses/i2c-qup.c +++ b/drivers/i2c/busses/i2c-qup.c @@ -213,14 +213,16 @@ static irqreturn_t qup_i2c_interrupt(int irq, void *dev) bus_err &= I2C_STATUS_ERROR_MASK; qup_err &= QUP_STATUS_ERROR_FLAGS; - if (qup_err) { - /* Clear Error interrupt */ + /* Clear the error bits in QUP_ERROR_FLAGS */ + if (qup_err) writel(qup_err, qup->base + QUP_ERROR_FLAGS); - goto done; - } - if (bus_err) { - /* Clear Error interrupt */ + /* Clear the error bits in QUP_I2C_STATUS */ + if (bus_err) + writel(bus_err, qup->base + QUP_I2C_STATUS); + + /* Reset the QUP State in case of error */ + if (qup_err || bus_err) { writel(QUP_RESET_STATE, qup->base + QUP_STATE); goto done; } -- 2.39.5