This is no good reason to not allow SMBus block writes longer than the
first one was. Lift this limitation, this makes the code more simple.
Signed-off-by: Jean Delvare <jdelvare@xxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
Changes since v1:
* Sent in a separate thread
* Added Guenter's Reviewed-by
* Fixed subject
Documentation/i2c/i2c-stub | 5 ++---
drivers/i2c/i2c-stub.c | 12 +++---------
2 files changed, 5 insertions(+), 12 deletions(-)
--- linux-3.16-rc4.orig/Documentation/i2c/i2c-stub 2014-07-12 09:41:26.508195718 +0200
+++ linux-3.16-rc4/Documentation/i2c/i2c-stub 2014-07-12 10:40:05.064578130 +0200
@@ -20,9 +20,8 @@ operations. This allows for continuous
EEPROMs, among others.
SMBus block commands must be written to configure an SMBus command for
-SMBus block operations. The first SMBus block write selects the block length.
-Subsequent writes can be partial. Block read commands always return
-the number of bytes selected with the first write.
+SMBus block operations. Writes can be partial. Block read commands always
+return the number of bytes selected with the largest write so far.
The typical use-case is like this:
1. load this module
--- linux-3.16-rc4.orig/drivers/i2c/i2c-stub.c 2014-07-12 09:41:26.508195718 +0200
+++ linux-3.16-rc4/drivers/i2c/i2c-stub.c 2014-07-12 11:19:40.908827183 +0200
@@ -254,13 +254,6 @@ static s32 stub_xfer(struct i2c_adapter
ret = -EINVAL;
break;
}
- if (b && len > b->len) {
- dev_dbg(&adap->dev,
- "Attempt to write more data (%d) than with initial SMBus block write (%d)\n",
- len, b->len);
- ret = -EINVAL;
- break;
- }
if (b == NULL) {
b = stub_find_block(&adap->dev, chip, command,
true);
@@ -268,9 +261,10 @@ static s32 stub_xfer(struct i2c_adapter
ret = -ENOMEM;
break;
}
- /* First write sets block length */
- b->len = len;
}
+ /* Largest write sets read block length */
+ if (len > b->len)
+ b->len = len;
for (i = 0; i < len; i++)
b->block[i] = data->block[i + 1];
/* update for byte and word commands */
--
Jean Delvare
SUSE L3 Support
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