[PATCH v4] i2c: imx-lpi2c: directly return ISR when detect a NACK
carlos.song at nxp.com
carlos.song at nxp.com
Wed Jul 26 20:03:47 PDT 2023
From: Carlos Song <carlos.song at nxp.com>
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 at nxp.com>
---
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
More information about the linux-arm-kernel
mailing list