This patch defines I2C_SMBUS_BLOCK_MAX and I2C_SMBUS_I2C_BLOCK_MAX,
those values were previously hardcoded in several places.
Part of the work was done by Ky?sti M?lkki. Original comment follows:
***
Message block size.
***
The patch also fixes an incorrect error message and a potential buffer
overrun.
diff -ru linux-2.4.25-pre4-k4/drivers/i2c/i2c-core.c linux-2.4.25-pre4-k5/drivers/i2c/i2c-core.c
--- linux-2.4.25-pre4-k4/drivers/i2c/i2c-core.c Sat Jan 10 20:27:50 2004
+++ linux-2.4.25-pre4-k5/drivers/i2c/i2c-core.c Sun Jan 11 10:33:12 2004
@@ -1062,8 +1062,8 @@
{
union i2c_smbus_data data;
int i;
- if (length > 32)
- length = 32;
+ if (length > I2C_SMBUS_BLOCK_MAX)
+ length = I2C_SMBUS_BLOCK_MAX;
for (i = 1; i <= length; i++)
data.block[i] = values[i-1];
data.block[0] = length;
@@ -1077,8 +1077,8 @@
{
union i2c_smbus_data data;
int i;
- if (length > 32)
- length = 32;
+ if (length > I2C_SMBUS_I2C_BLOCK_MAX)
+ length = I2C_SMBUS_I2C_BLOCK_MAX;
for (i = 1; i <= length; i++)
data.block[i] = values[i-1];
data.block[0] = length;
@@ -1152,10 +1152,10 @@
return -1;
} else {
msg[0].len = data->block[0] + 2;
- if (msg[0].len > 34) {
+ if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
printk(KERN_ERR "i2c-core.o: smbus_access called with "
"invalid block write size (%d)\n",
- msg[0].len);
+ data->block[0]);
return -1;
}
for (i = 1; i <= msg[0].len; i++)
diff -ru linux-2.4.25-pre4-k4/include/linux/i2c.h linux-2.4.25-pre4-k5/include/linux/i2c.h
--- linux-2.4.25-pre4-k4/include/linux/i2c.h Sat Jan 10 20:27:55 2004
+++ linux-2.4.25-pre4-k5/include/linux/i2c.h Sun Jan 11 10:46:48 2004
@@ -413,10 +413,13 @@
/*
* Data for SMBus Messages
*/
+#define I2C_SMBUS_BLOCK_MAX 32 /* As specified in SMBus standard */
+#define I2C_SMBUS_I2C_BLOCK_MAX 32 /* Not specified but we use same structure */
union i2c_smbus_data {
__u8 byte;
__u16 word;
- __u8 block[33]; /* block[0] is used for length */
+ __u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
+ /* one more for read length in block process call */
};
/* smbus_access read or write markers */
--
Jean Delvare
http://www.ensicaen.ismra.fr/~delvare/
