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authorJean Delvare <khali@linux-fr.org>2010-05-21 18:40:54 +0200
committerJean Delvare <khali@linux-fr.org>2010-05-21 18:40:54 +0200
commitadff687d8cb0ed62b147a7e1d277846b3130d593 (patch)
tree78fa2c799505f5875bee109d2975cb7eaaccd210
parent7a9b149212f3716c598afe973b6261fd58453b7a (diff)
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i2c-i801: Let the user disable selected driver features
Let the user disable selected features normally supported by the device. This makes it possible to work around possible driver or hardware bugs if the feature in question doesn't work as intended for whatever reason. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Felix Rubinstein <felixru@gmail.com>
-rw-r--r--Documentation/i2c/busses/i2c-i8018
-rw-r--r--drivers/i2c/busses/i2c-i801.c21
2 files changed, 27 insertions, 2 deletions
diff --git a/Documentation/i2c/busses/i2c-i801 b/Documentation/i2c/busses/i2c-i801
index e1bb5b26169..e307914a3ed 100644
--- a/Documentation/i2c/busses/i2c-i801
+++ b/Documentation/i2c/busses/i2c-i801
@@ -27,7 +27,13 @@ Authors:
Module Parameters
-----------------
-None.
+* disable_features (bit vector)
+Disable selected features normally supported by the device. This makes it
+possible to work around possible driver or hardware bugs if the feature in
+question doesn't work as intended for whatever reason. Bit values:
+ 1 disable SMBus PEC
+ 2 disable the block buffer
+ 8 disable the I2C block read functionality
Description
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 299b918455a..f0fef343e19 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -138,6 +138,17 @@ static struct pci_dev *I801_dev;
#define FEATURE_I2C_BLOCK_READ (1 << 3)
static unsigned int i801_features;
+static const char *i801_feature_names[] = {
+ "SMBus PEC",
+ "Block buffer",
+ "Block process call",
+ "I2C block read",
+};
+
+static unsigned int disable_features;
+module_param(disable_features, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(disable_features, "Disable selected driver features");
+
/* Make sure the SMBus host is ready to start transmitting.
Return 0 if it is, -EBUSY if it is not. */
static int i801_check_pre(void)
@@ -692,7 +703,7 @@ static void __devinit dmi_check_onboard_devices(const struct dmi_header *dm,
static int __devinit i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
unsigned char temp;
- int err;
+ int err, i;
#if defined CONFIG_SENSORS_FSCHMD || defined CONFIG_SENSORS_FSCHMD_MODULE
const char *vendor;
#endif
@@ -720,6 +731,14 @@ static int __devinit i801_probe(struct pci_dev *dev, const struct pci_device_id
break;
}
+ /* Disable features on user request */
+ for (i = 0; i < ARRAY_SIZE(i801_feature_names); i++) {
+ if (i801_features & disable_features & (1 << i))
+ dev_notice(&dev->dev, "%s disabled by user\n",
+ i801_feature_names[i]);
+ }
+ i801_features &= ~disable_features;
+
err = pci_enable_device(dev);
if (err) {
dev_err(&dev->dev, "Failed to enable SMBus PCI device (%d)\n",