HID: cp2112: fix to force single data-report reply

6debce6f · Antonio Borneo <[email protected]> · 2015-06-21 14:20:25 +08:00

Current implementation of cp2112_raw_event() only accepts one data report at a
time. If last received data report is not fully handled yet, a new incoming
data report will overwrite it. In such case we don't guaranteed to propagate
the correct incoming data.

The trivial fix implemented here forces a single report at a time by requesting
in cp2112_read() no more than 61 byte of data, which is the payload size of a
single data report.

Cc: [email protected]
Signed-off-by: Antonio Borneo <[email protected]>
Tested-by: Ellen Wang <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>

Commit: 6debce6f4e787a8eb4cec94e7afa85fb4f40db27
Parents: 9633920e

Changes

1 files changed · +2 −0

File	Status	Add	Del	Content
drivers/hid/hid-cp2112.c	modified	+2	−0	View file

drivers/hid/hid-cp2112.c

View file

diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c
index 3318de6..a2dbbbe 100644
--- a/drivers/hid/hid-cp2112.c
+++ b/drivers/hid/hid-cp2112.c
@@ -356,6 +356,8 @@ static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
 	struct cp2112_force_read_report report;
 	int ret;
 
+	if (size > sizeof(dev->read_data))
+		size = sizeof(dev->read_data);
 	report.report = CP2112_DATA_READ_FORCE_SEND;
 	report.length = cpu_to_be16(size);
 