From 224acec66433ee36f58531d815e61498a407ac44 Mon Sep 17 00:00:00 2001 From: Carlos Song Date: Thu, 27 Jul 2023 11:03:47 +0800 Subject: [PATCH] i2c: imx-lpi2c: directly return ISR when detect a NACK 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 Reviewed-by: Andi Shyti Link: https://lore.kernel.org/r/20230727030347.3552992-1-carlos.song@nxp.com Signed-off-by: Andi Shyti --- 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 c3287c8..636ad32 100644 --- a/drivers/i2c/busses/i2c-imx-lpi2c.c +++ b/drivers/i2c/busses/i2c-imx-lpi2c.c @@ -514,14 +514,12 @@ 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; } -- 2.7.4