[PATCH 1/4] i2c-i801: Use wait_event_timeout to wait for interrupts

Jean Delvare
2014-11-10T21:30:33Z

Some systems have been reported to have trouble with interrupts. Use
wait_event_timeout() instead of wait_event() so we don't get stuck in
that case, and log the problem.

Signed-off-by: Jean Delvare <jdelvare-l3A5Bk7waGM@public.gmane.org>
Cc: Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>
---
drivers/i2c/busses/i2c-i801.c | 25 ++++++++++++++++++++++---
1 file changed, 22 insertions(+), 3 deletions(-)

--- linux-3.18-rc4.orig/drivers/i2c/busses/i2c-i801.c 2014-11-10 22:26:47.212135115 +0100
+++ linux-3.18-rc4/drivers/i2c/busses/i2c-i801.c 2014-11-10 22:29:18.040417276 +0100
@@ -2,7 +2,7 @@
Copyright (c) 1998 - 2002 Frodo Looijaard <frodol-B0qZmFHriGg@public.gmane.org>,
Philip Edelbrock <phil-KXOFo5pg7o1l57MIdRCFDg@public.gmane.org>, and Mark D. Studebaker
<mdsxyz123-/E1597aS9LQAvxtiuMwx3w@public.gmane.org>
- Copyright (C) 2007 - 2012 Jean Delvare <jdelvare-l3A5Bk7waGM@public.gmane.org>
+ Copyright (C) 2007 - 2014 Jean Delvare <jdelvare-l3A5Bk7waGM@public.gmane.org>
Copyright (C) 2010 Intel Corporation,
David Woodhouse <dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>

@@ -373,6 +373,7 @@ static int i801_transaction(struct i801_
{
int status;
int result;
+ const struct i2c_adapter *adap = &priv->adapter;

result = i801_check_pre(priv);
if (result < 0)
@@ -381,7 +382,14 @@ static int i801_transaction(struct i801_
if (priv->features & FEATURE_IRQ) {
outb_p(xact | SMBHSTCNT_INTREN | SMBHSTCNT_START,
SMBHSTCNT(priv));
- wait_event(priv->waitq, (status = priv->status));
+ result = wait_event_timeout(priv->waitq,
+ (status = priv->status),
+ adap->timeout);
+ if (!result) {
+ status = -ETIMEDOUT;
+ dev_warn(&priv->pci_dev->dev,
+ "Timeout waiting for interrupt!\n");
+ }
priv->status = 0;
return i801_check_post(priv, status);
}
@@ -529,6 +537,7 @@ static int i801_block_transaction_byte_b
int smbcmd;
int status;
int result;
+ const struct i2c_adapter *adap = &priv->adapter;

result = i801_check_pre(priv);
if (result < 0)
@@ -557,7 +566,14 @@ static int i801_block_transaction_byte_b
priv->data = &data->block[1];

outb_p(priv->cmd | SMBHSTCNT_START, SMBHSTCNT(priv));
- wait_event(priv->waitq, (status = priv->status));
+ result = wait_event_timeout(priv->waitq,
+ (status = priv->status),
+ adap->timeout);
+ if (!result) {
+ status = -ETIMEDOUT;
+ dev_warn(&priv->pci_dev->dev,
+ "Timeout waiting for interrupt!\n");
+ }
priv->status = 0;
return i801_check_post(priv, status);
}
@@ -1215,6 +1231,9 @@ static int i801_probe(struct pci_dev *de
outb_p(inb_p(SMBAUXCTL(priv)) &
~(SMBAUXCTL_CRC | SMBAUXCTL_E32B), SMBAUXCTL(priv));

+ /* Default timeout in interrupt mode: 200 ms */
+ priv->adapter.timeout = HZ / 5;
+
if (priv->features & FEATURE_IRQ) {
init_waitqueue_head(&priv->waitq);