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From:   Jian Zhang <zhangjian.3032@bytedance.com>
To:     brendan.higgins@linux.dev, benh@kernel.crashing.org,
        joel@jms.id.au, andrew@aj.id.au
Cc:     zhangjian3032@gmail.com, yulei.sh@bytedance.com,
        xiexinnan@bytedance.com, Andi Shyti <andi.shyti@kernel.org>,
        Tommy Huang <tommy_huang@aspeedtech.com>,
        Wolfram Sang <wsa@kernel.org>,
        linux-i2c@vger.kernel.org (open list:ARM/ASPEED I2C DRIVER),
        openbmc@lists.ozlabs.org (moderated list:ARM/ASPEED I2C DRIVER),
        linux-arm-kernel@lists.infradead.org (moderated list:ARM/ASPEED MACHINE
        SUPPORT),
        linux-aspeed@lists.ozlabs.org (moderated list:ARM/ASPEED MACHINE
        SUPPORT), linux-kernel@vger.kernel.org (open list)
Subject: [PATCH v2] i2c: aspeed: Fix i2c bus hang in slave read
Date:   Wed, 27 Sep 2023 23:42:43 +0800
Message-Id: <20230927154244.3774670-1-zhangjian.3032@bytedance.com>
MIME-Version: 1.0
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When the `CONFIG_I2C_SLAVE` option is enabled and the device operates
as a slave, a situation arises where the master sends a START signal
without the accompanying STOP signal. This action results in a
persistent I2C bus timeout. The core issue stems from the fact that
the i2c controller remains in a slave read state without a timeout
mechanism. As a consequence, the bus perpetually experiences timeouts.

In this case, the i2c bus will be reset, but the slave_state reset is
missing.

Fixes: fee465150b45 ("i2c: aspeed: Reset the i2c controller when timeout occurs")
Signed-off-by: Jian Zhang <zhangjian.3032@bytedance.com>
---
 drivers/i2c/busses/i2c-aspeed.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
index 5a416b39b818..18f618625472 100644
--- a/drivers/i2c/busses/i2c-aspeed.c
+++ b/drivers/i2c/busses/i2c-aspeed.c
@@ -933,6 +933,7 @@ static int aspeed_i2c_init(struct aspeed_i2c_bus *bus,
 	/* If slave has already been registered, re-enable it. */
 	if (bus->slave)
 		__aspeed_i2c_reg_slave(bus, bus->slave->addr);
+	bus->slave_state = ASPEED_I2C_SLAVE_INACTIVE;
 #endif /* CONFIG_I2C_SLAVE */

 	/* Set interrupt generation of I2C controller */
--
2.30.2