From: carlos.song@nxp.com
To: andi.shyti@kernel.org, aisheng.dong@nxp.com, shawnguo@kernel.org,
s.hauer@pengutronix.de, kernel@pengutronix.de,
festevam@gmail.com
Cc: carlos.song@nxp.com, xiaoning.wang@nxp.com, haibo.chen@nxp.com,
linux-imx@nxp.com, linux-i2c@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v4] i2c: imx-lpi2c: directly return ISR when detect a NACK
Date: Thu, 27 Jul 2023 11:03:47 +0800 [thread overview]
Message-ID: <20230727030347.3552992-1-carlos.song@nxp.com> (raw)
From: Carlos Song <carlos.song@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@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
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next reply other threads:[~2023-07-27 3:00 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-27 3:03 carlos.song [this message]
2023-07-27 8:38 ` [PATCH v4] i2c: imx-lpi2c: directly return ISR when detect a NACK Andi Shyti
2023-08-02 20:10 ` Andi Shyti
2023-08-14 15:02 ` Wolfram Sang
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