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From: Reid Tonking <reidt@ti.com>
To: <tony@atomide.com>, <vigneshr@ti.com>, <aaro.koskinen@iki.fi>,
	<jmkrzyszt@gmail.com>
Cc: <linux-omap@vger.kernel.org>, <linux-i2c@vger.kernel.org>,
	Reid Tonking <reidt@ti.com>
Subject: [PATCH] i2c: omap: Fix standard mode false ACK readings
Date: Mon, 24 Apr 2023 14:53:44 -0500	[thread overview]
Message-ID: <20230424195344.627861-1-reidt@ti.com> (raw)

Using standard mode, rare false ACK responses were appearing with
i2cdetect tool. This was happening due to NACK interrupt triggering
ISR thread before register access interrupt was ready. Removing the
NACK interrupt's ability to trigger ISR thread lets register access
ready interrupt do this instead.

Fixes: 3b2f8f82dad7 ("i2c: omap: switch to threaded IRQ support")

Signed-off-by: Reid Tonking <reidt@ti.com>
---
Fixes: LCPD-29949

 drivers/i2c/busses/i2c-omap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index f9ae520aed22..7ec252199706 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -1058,7 +1058,7 @@ omap_i2c_isr(int irq, void *dev_id)
 	u16 stat;
 
 	stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
-	mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);
+	mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG) & ~OMAP_I2C_STAT_NACK;
 
 	if (stat & mask)
 		ret = IRQ_WAKE_THREAD;
-- 
2.34.1


             reply	other threads:[~2023-04-24 19:54 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-24 19:53 Reid Tonking [this message]
2023-04-25 12:45 ` [PATCH] i2c: omap: Fix standard mode false ACK readings Andi Shyti
     [not found]   ` <20230425145610.j3ljepycclr3i42t@reidt-t5600.dhcp.ti.com>
2023-04-25 15:51     ` Reid Tonking

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