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From: Reid Tonking <reidt@ti.com>
To: <tony@atomide.com>, <aaro.koskinen@iki.fi>, <jmkrzyszt@gmail.com>,
	<vigneshr@ti.com>
Cc: <linux-omap@vger.kernel.org>, <linux-i2c@vger.kernel.org>,
	<stable@vger.kernel.org>, Reid Tonking <reidt@ti.com>
Subject: [PATCH v2] i2c: omap: Fix standard mode false ACK readings
Date: Wed, 26 Apr 2023 14:49:56 -0500	[thread overview]
Message-ID: <20230426194956.689756-1-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.

Cc: <stable@vger.kernel.org> # v3.7+
Fixes: 3b2f8f82dad7 ("i2c: omap: switch to threaded IRQ support")
Signed-off-by: Reid Tonking <reidt@ti.com>
---
 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 2b4e2be51318..4199f57a6bf2 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:[~2023-04-26 19:50 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-26 19:49 Reid Tonking [this message]
2023-04-27 13:18 ` [PATCH v2] i2c: omap: Fix standard mode false ACK readings Raghavendra, Vignesh
2023-04-28  7:43   ` Tony Lindgren
2023-04-28 18:30     ` Reid Tonking
2023-05-03  6:03       ` Tony Lindgren
2024-09-11  9:40       ` H. Nikolaus Schaller
2024-09-13 12:09         ` Andreas Kemnade
2024-09-13 12:28           ` H. Nikolaus Schaller
2024-09-13 13:32             ` Andreas Kemnade
2024-09-13 15:01               ` H. Nikolaus Schaller
2024-11-06  9:23         ` Andreas Kemnade
2024-11-06 12:16           ` H. Nikolaus Schaller
2024-11-06 15:09             ` H. Nikolaus Schaller
2025-02-02 22:42               ` Ing. Josua Mayer
2023-04-30  5:52 ` Wolfram Sang

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