From: Carlos Song <carlos.song@xxxxxxx> A NACK flag in ISR means i2c bus error. In such condition, there is no need to do read/write operation. In this patch, i2c will check MSR_NDF, MSR_RDF and MSR_TDF flag in turn, it's making mutually exclusive NACK/read/write. So when a NACK is received(MSR_NDF), i2c will return ISR directly and then stop i2c transfer. Signed-off-by: Carlos Song <carlos.song@xxxxxxx> --- drivers/i2c/busses/i2c-imx-lpi2c.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c index 150d923ca7f1..9a3e3a1bc4ee 100644 --- a/drivers/i2c/busses/i2c-imx-lpi2c.c +++ b/drivers/i2c/busses/i2c-imx-lpi2c.c @@ -517,14 +517,12 @@ static irqreturn_t lpi2c_imx_isr(int irq, void *dev_id) temp = readl(lpi2c_imx->base + LPI2C_MSR); temp &= enabled; - if (temp & MSR_RDF) - lpi2c_imx_read_rxfifo(lpi2c_imx); - - if (temp & MSR_TDF) - lpi2c_imx_write_txfifo(lpi2c_imx); - if (temp & MSR_NDF) complete(&lpi2c_imx->complete); + else if (temp & MSR_RDF) + lpi2c_imx_read_rxfifo(lpi2c_imx); + else if (temp & MSR_TDF) + lpi2c_imx_write_txfifo(lpi2c_imx); return IRQ_HANDLED; } -- 2.34.1
