linux-kernel - [PATCH] i2c: aspeed: Reset the i2c controller when timeout occurs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230904012505.340455-1-tommy_huang@aspeedtech.com>
Date:   Mon, 4 Sep 2023 09:25:05 +0800
From:   Tommy Huang <tommy_huang@...eedtech.com>
To:     <brendan.higgins@...ux.dev>, <andi.shyti@...nel.org>,
        <p.zabel@...gutronix.de>, <linux-i2c@...r.kernel.org>,
        <openbmc@...ts.ozlabs.org>
CC:     <benh@...nel.crashing.org>, <joel@....id.au>, <andrew@...id.au>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-aspeed@...ts.ozlabs.org>, <jae.hyun.yoo@...ux.intel.com>,
        <linux-kernel@...r.kernel.org>, <BMC-SW@...eedtech.com>,
        <stable@...r.kernel.org>
Subject: [PATCH] i2c: aspeed: Reset the i2c controller when timeout occurs

Reset the i2c controller when an i2c transfer timeout occurs.
The remaining interrupts and device should be reset to avoid
unpredictable controller behavior.

Fixes: 2e57b7cebb98 ("i2c: aspeed: Add multi-master use case support")
Cc: Jae Hyun Yoo <jae.hyun.yoo@...ux.intel.com>
Cc: <stable@...r.kernel.org> # v5.1+

Signed-off-by: Tommy Huang <tommy_huang@...eedtech.com>
---
 drivers/i2c/busses/i2c-aspeed.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
index 2e5acfeb76c8..5a416b39b818 100644
--- a/drivers/i2c/busses/i2c-aspeed.c
+++ b/drivers/i2c/busses/i2c-aspeed.c
@@ -698,13 +698,16 @@ static int aspeed_i2c_master_xfer(struct i2c_adapter *adap,
 
 	if (time_left == 0) {
 		/*
-		 * If timed out and bus is still busy in a multi master
-		 * environment, attempt recovery at here.
+		 * In a multi-master setup, if a timeout occurs, attempt
+		 * recovery. But if the bus is idle, we still need to reset the
+		 * i2c controller to clear the remaining interrupts.
 		 */
 		if (bus->multi_master &&
 		    (readl(bus->base + ASPEED_I2C_CMD_REG) &
 		     ASPEED_I2CD_BUS_BUSY_STS))
 			aspeed_i2c_recover_bus(bus);
+		else
+			aspeed_i2c_reset(bus);
 
 		/*
 		 * If timed out and the state is still pending, drop the pending
-- 
2.25.1