Commit 224acec6 authored by Carlos Song's avatar Carlos Song Committed by Andi Shyti
Browse files

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: default avatarCarlos Song <carlos.song@nxp.com>
Reviewed-by: default avatarAndi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20230727030347.3552992-1-carlos.song@nxp.com


Signed-off-by: default avatarAndi Shyti <andi.shyti@kernel.org>
parent 52a93d39

drivers/i2c/busses/i2c-imx-lpi2c.c

+4 −6
Original line number Diff line number Diff line
@@ -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;

}