This is a note to let you know that I've just added the patch titled
i2c: npcm7xx: Fix callback completion ordering
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
i2c-npcm7xx-fix-callback-completion-ordering.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 92c20b907a5efff879b46af0c656834a20dca143
Author: William A. Kennington III <william@xxxxxxxxxxxxxxx>
Date: Sat Sep 23 18:02:14 2023 -0700
i2c: npcm7xx: Fix callback completion ordering
[ Upstream commit 92e73d807b68b2214fcafca4e130b5300a9d4b3c ]
Sometimes, our completions race with new master transfers and override
the bus->operation and bus->master_or_slave variables. This causes
transactions to timeout and kernel crashes less frequently.
To remedy this, we re-order all completions to the very end of the
function.
Fixes: 56a1485b102e ("i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver")
Signed-off-by: William A. Kennington III <william@xxxxxxxxxxxxxxx>
Reviewed-by: Tali Perry <tali.perry1@xxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
index c1b6797372409..73c808ef1bfe5 100644
--- a/drivers/i2c/busses/i2c-npcm7xx.c
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -675,6 +675,7 @@ static void npcm_i2c_callback(struct npcm_i2c *bus,
{
struct i2c_msg *msgs;
int msgs_num;
+ bool do_complete = false;
msgs = bus->msgs;
msgs_num = bus->msgs_num;
@@ -701,23 +702,17 @@ static void npcm_i2c_callback(struct npcm_i2c *bus,
msgs[1].flags & I2C_M_RD)
msgs[1].len = info;
}
- if (completion_done(&bus->cmd_complete) == false)
- complete(&bus->cmd_complete);
- break;
-
+ do_complete = true;
+ break;
case I2C_NACK_IND:
/* MASTER transmit got a NACK before tx all bytes */
bus->cmd_err = -ENXIO;
- if (bus->master_or_slave == I2C_MASTER)
- complete(&bus->cmd_complete);
-
+ do_complete = true;
break;
case I2C_BUS_ERR_IND:
/* Bus error */
bus->cmd_err = -EAGAIN;
- if (bus->master_or_slave == I2C_MASTER)
- complete(&bus->cmd_complete);
-
+ do_complete = true;
break;
case I2C_WAKE_UP_IND:
/* I2C wake up */
@@ -731,6 +726,8 @@ static void npcm_i2c_callback(struct npcm_i2c *bus,
if (bus->slave)
bus->master_or_slave = I2C_SLAVE;
#endif
+ if (do_complete)
+ complete(&bus->cmd_complete);
}
static u8 npcm_i2c_fifo_usage(struct npcm_i2c *bus)
