[PATCH] i2c: i2c-mv64xxx fix transaction abortion
When the i2c-mv64xxx i2c driver is signalled to abort a transaction,
it aborts it immediately by issuing a stop condition on the bus.
This violates the i2c protocol and can cause what appears to be an i2c
bus hang. This patch delays issuing the stop condition until the i2c
device can reasonably expect a stop condition.
Also includes a minor fixup.
Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index 81031eb..22781d8 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -1,6 +1,4 @@
/*
- * drivers/i2c/busses/i2c-mv64xxx.c
- *
* Driver for the i2c controller on the Marvell line of host bridges for MIPS
* and PPC (e.g, gt642[46]0, mv643[46]0, mv644[46]0).
*
@@ -65,7 +63,6 @@
MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK,
MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK,
MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA,
- MV64XXX_I2C_STATE_ABORTING,
};
/* Driver actions */
@@ -85,6 +82,7 @@
int irq;
u32 state;
u32 action;
+ u32 aborting;
u32 cntl_bits;
void __iomem *reg_base;
u32 reg_base_p;
@@ -122,12 +120,6 @@
return;
}
- if (drv_data->state == MV64XXX_I2C_STATE_ABORTING) {
- drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
- drv_data->state = MV64XXX_I2C_STATE_IDLE;
- return;
- }
-
/* The status from the ctlr [mostly] tells us what to do next */
switch (status) {
/* Start condition interrupt */
@@ -148,14 +140,16 @@
/* FALLTHRU */
case MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */
case MV64XXX_I2C_STATUS_MAST_WR_ACK: /* 0x28 */
- if (drv_data->bytes_left > 0) {
+ if ((drv_data->bytes_left == 0)
+ || (drv_data->aborting
+ && (drv_data->byte_posn != 0))) {
+ drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
+ drv_data->state = MV64XXX_I2C_STATE_IDLE;
+ } else {
drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA;
drv_data->state =
MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK;
drv_data->bytes_left--;
- } else {
- drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
- drv_data->state = MV64XXX_I2C_STATE_IDLE;
}
break;
@@ -184,7 +178,7 @@
}
drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA;
- if (drv_data->bytes_left == 1)
+ if ((drv_data->bytes_left == 1) || drv_data->aborting)
drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_ACK;
break;
@@ -320,6 +314,7 @@
drv_data->msg = msg;
drv_data->byte_posn = 0;
drv_data->bytes_left = msg->len;
+ drv_data->aborting = 0;
drv_data->rc = 0;
drv_data->cntl_bits = MV64XXX_I2C_REG_CONTROL_ACK |
MV64XXX_I2C_REG_CONTROL_INTEN | MV64XXX_I2C_REG_CONTROL_TWSIEN;
@@ -359,17 +354,19 @@
}
if (abort && drv_data->block) {
- drv_data->state = MV64XXX_I2C_STATE_ABORTING;
+ drv_data->aborting = 1;
spin_unlock_irqrestore(&drv_data->lock, flags);
time_left = wait_event_timeout(drv_data->waitq,
!drv_data->block,
msecs_to_jiffies(drv_data->adapter.timeout));
- if (time_left <= 0) {
+ if ((time_left <= 0) && drv_data->block) {
drv_data->state = MV64XXX_I2C_STATE_IDLE;
dev_err(&drv_data->adapter.dev,
- "mv64xxx: I2C bus locked\n");
+ "mv64xxx: I2C bus locked, block: %d, "
+ "time_left: %d\n", drv_data->block,
+ (int)time_left);
}
} else
spin_unlock_irqrestore(&drv_data->lock, flags);
@@ -510,7 +507,7 @@
goto exit_kfree;
}
- strncpy(drv_data->adapter.name, MV64XXX_I2C_CTLR_NAME " adapter",
+ strlcpy(drv_data->adapter.name, MV64XXX_I2C_CTLR_NAME " adapter",
I2C_NAME_SIZE);
init_waitqueue_head(&drv_data->waitq);