From mboxrd@z Thu Jan 1 00:00:00 1970 From: eric.y.miao@gmail.com (Eric Miao) Date: Fri, 5 Feb 2010 03:12:16 -0800 Subject: [PATCH 1/1] fix i2c_msg.len not aligning with i2c_master_send In-Reply-To: <309424b61002042151i2a762d41md3521a820fd45622@mail.gmail.com> References: <309424b61002032204y37307236q94ab3a502b0526e0@mail.gmail.com> <20100204103530.65429c04@hyperion.delvare> <309424b61002040438i2fae055dt2d3ef528eae99b48@mail.gmail.com> <20100204141451.3e0f865e@hyperion.delvare> <309424b61002042151i2a762d41md3521a820fd45622@mail.gmail.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org > Hi, Jean > > Thanks for your instruction. > Here is patch to modify some comments of i2c_master_send & > i2c_master_recv, is this OK. > Where's the screaming things, dude? > Thanks > Zhangfei > > From 30fbf1ebf1facba3d280c887e2ecfd0499e7b04b Mon Sep 17 00:00:00 2001 > From: Zhangfei Gao > 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 > --- > ?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 > ?* > ?* 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); > -- > 1.6.0.4 >