> * Allocated bit 4 (I2C_SMBUS3_BLOCK=0x10), to simplify Smbus2
> compatibility: I2C_SMBUS_*BLOCK* = (<old type>|0x10)
I think the code becomes easier to understand, if we use new transfer
types a bit more explicitly. Also, I am not sure of the extra bit
because it is not clearly visible that types >= 16 and <= 31 will have a
special meaning. We could do like this if we sacrifice one number for
an unused BROKEN with 255 byte:
-#define I2C_SMBUS_BLOCK_DATA 5
+#define I2C_SMBUS2_BLOCK_DATA 5 /* 32 byte only, deprecated */
-#define I2C_SMBUS_I2C_BLOCK_BROKEN 6
+#define I2C_SMBUS2_I2C_BLOCK_BROKEN 6 /* 32 byte only, deprecated */
-#define I2C_SMBUS_BLOCK_PROC_CALL 7 /* SMBus 2.0 */
+#define I2C_SMBUS2_BLOCK_PROC_CALL 7 /* SMBus 2.0, 32 byte only, deprecated */
-#define I2C_SMBUS_I2C_BLOCK_DATA 8
+#define I2C_SMBUS2_I2C_BLOCK_DATA 8 /* 32 byte only, deprecated */
+#define I2C_SMBUS_BLOCK_DATA 9
+#define I2C_SMBUS_I2C_BLOCK_BROKEN 10 /* FIXME: probably say "don't use" here
+#define I2C_SMBUS_BLOCK_PROC_CALL 11 /* SMBus >= 2.0 */
+#define I2C_SMBUS_I2C_BLOCK_DATA 12
>
> + user_len = kmalloc_array(nmsgs, sizeof(*user_len), GFP_KERNEL);
> + if (!user_len) {
> + res = -ENOMEM;
> + goto out;
> + }
Maybe on stack? I2C_RDWR_IOCTL_MAX_MSGS will ensure this will stay at a
sane value.
> @@ -313,7 +357,19 @@ static noinline int i2cdev_ioctl_smbus(struct i2c_client *client,
> union i2c_smbus_data __user *data)
> {
> union i2c_smbus_data temp = {};
> - int datasize, res;
> + int block_max, datasize, res;
> +
'size' is really a misleading name :(
+ if (size <= I2C_SMBUS2_I2C_BLOCK_DATA) {
+ if (size >= I2C_SMBUS2_BLOCK_DATA)
+ size += I2C_SMBUS_BLOCK_DATA - I2C_SMBUS2_BLOCK_DATA;
+ block_max = I2C_SMBUS_BLOCK_MAX;
+ } else {
+ block_max = I2C_SMBUS3_BLOCK_MAX;
+ }
Would this work, too?
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