[PATCH v1] HID: cp2112: fix I2C_SMBUS_BYTE write

[PATCH v1] HID: cp2112: fix I2C_SMBUS_BYTE write

[Ellen Wang]

When doing an I2C_SMBUS_BYTE write (one byte write, no address),
the data to be written is in "command" not "data->byte".
---
 drivers/hid/hid-cp2112.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c
index a3703b8..7afc3fc 100644
--- a/drivers/hid/hid-cp2112.c
+++ b/drivers/hid/hid-cp2112.c
@@ -606,7 +606,7 @@ static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
 		if (I2C_SMBUS_READ == read_write)
 			count = cp2112_read_req(buf, addr, read_length);
 		else
-			count = cp2112_write_req(buf, addr, data->byte, NULL,
+			count = cp2112_write_req(buf, addr, command, NULL,
 						 0);
 		break;
 	case I2C_SMBUS_BYTE_DATA:
-- 
1.9.1

Re: [PATCH v1] HID: cp2112: fix I2C_SMBUS_BYTE write

[Jiri Kosina]

On Thu, 9 Jul 2015, Ellen Wang wrote:

> When doing an I2C_SMBUS_BYTE write (one byte write, no address),
> the data to be written is in "command" not "data->byte".

This is missing Signoff.

How serious is this bug in practice? Is this 4.2 material?

Thanks,

-- 
Jiri Kosina
SUSE Labs

Re: [PATCH v1] HID: cp2112: fix I2C_SMBUS_BYTE write

[Ellen Wang]

On 7/13/2015 4:20 AM, Jiri Kosina wrote:
> On Thu, 9 Jul 2015, Ellen Wang wrote:
>
>> When doing an I2C_SMBUS_BYTE write (one byte write, no address),
>> the data to be written is in "command" not "data->byte".
>
> This is missing Signoff.

Sorry.  I submitted v2.

> How serious is this bug in practice? Is this 4.2 material?

The driver segfaults without the fix, and this is a common operation. 
On the other hand, the cp2112 is an uncommon device.

(I would personally like all the cp2112 fixes to be in 4.1 eventually. 
They are all important functional improvements.)