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@xxxxxxxxxxx> > 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@xxxxxxxxxxx> > --- > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
