Re: [PATCH 1/1] fix i2c_msg.len not aligning with i2c_master_send

[Jean Delvare <khali@linux-fr.org>]

On Fri, 5 Feb 2010 13:51:19 +0800, zhangfei gao wrote:
> Thanks for your instruction.
> Here is patch to modify some comments of i2c_master_send &
> i2c_master_recv, is this OK.
> 
> Thanks
> Zhangfei
> 
> From 30fbf1ebf1facba3d280c887e2ecfd0499e7b04b Mon Sep 17 00:00:00 2001
> From: Zhangfei Gao <zgao6@marvell.com>
> Date: Sat, 6 Feb 2010 05:38:59 +0800
> Subject: [PATCH] i2c: notes of i2c_master_send & i2c_master_recv
> 
> 	i2c_master_send & i2c_master_recv not support more than 64bytes
> transfer, since msg.len is __u16 type
> 
> Signed-off-by: Zhangfei Gao <zgao6@marvell.com>
> ---
>  Documentation/i2c/writing-clients |    3 ++-
>  drivers/i2c/i2c-core.c            |    4 ++--
>  include/linux/i2c.h               |    1 +
>  3 files changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/i2c/writing-clients
> b/Documentation/i2c/writing-clients
> index 7860aaf..929a3c3 100644
> --- a/Documentation/i2c/writing-clients
> +++ b/Documentation/i2c/writing-clients
> @@ -318,7 +318,8 @@ Plain I2C communication
>  These routines read and write some bytes from/to a client. The client
>  contains the i2c address, so you do not have to include it. The second
>  parameter contains the bytes to read/write, the third the number of bytes
> -to read/write (must be less than the length of the buffer.) Returned is
> +to read/write (must be less than the length of the buffer, also should be
> +less than 64K since msg.len is __u16 type.) Returned is
>  the actual number of bytes read/written.
> 
>  	int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msg,
> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
> index 8d80fce..9607dcc 100644
> --- a/drivers/i2c/i2c-core.c
> +++ b/drivers/i2c/i2c-core.c
> @@ -1112,7 +1112,7 @@ EXPORT_SYMBOL(i2c_transfer);
>   * i2c_master_send - issue a single I2C message in master transmit mode
>   * @client: Handle to slave device
>   * @buf: Data that will be written to the slave
> - * @count: How many bytes to write
> + * @count: How many bytes to write, should be less than 64K since
> msg.len is u16

Your patch was line-wrapped by your e-mail client, so it doesn't apply.
I've fixed it this time, but please make sure it doesn't happen again
for future patches you send.

>   *
>   * Returns negative errno, or else the number of bytes written.
>   */
> @@ -1139,7 +1139,7 @@ EXPORT_SYMBOL(i2c_master_send);
>   * i2c_master_recv - issue a single I2C message in master receive mode
>   * @client: Handle to slave device
>   * @buf: Where to store data read from slave
> - * @count: How many bytes to read
> + * @count: How many bytes to read, should be less than 64K since msg.len is u16
>   *
>   * Returns negative errno, or else the number of bytes read.
>   */
> diff --git a/include/linux/i2c.h b/include/linux/i2c.h
> index 57d41b0..b2dea18 100644
> --- a/include/linux/i2c.h
> +++ b/include/linux/i2c.h
> @@ -53,6 +53,7 @@ struct i2c_board_info;
>   * on a bus (or read from them). Apart from two basic transfer functions to
>   * transmit one message at a time, a more complex version can be used to
>   * transmit an arbitrary number of messages without interruption.
> + * Parameter count should be less than 64K since msg.len is __u16
>   */
>  extern int i2c_master_send(struct i2c_client *client, const char *buf,
>  			   int count);

Patch applied with minor reformatting, thanks.

-- 
Jean Delvare