A common method of probing an i2c bus is trying to do a zero-length write.
Handle this case by checking the length first before decrementing it.
This is actually important, since attempting a zero-length write is one
of the ways that i2cdetect and i2c_new_probed_device detect whether
there is device present on the bus with a given address.
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
(cherry picked from commit
26883c31b0799e76edf8f0ea8be48b64e09b2a7d)
Change-Id: I92da830afe16684d9d3e9f2cf80a667d874ee602
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
u32 val, loop;
val = loop = 0;
- do {
- val |= *buf++ << (8 * loop);
- } while (--len && ++loop < 4);
+ while (len && loop < 4) {
+ val |= *buf++ << (8 * loop++);
+ len -= 1;
+ }
I915_WRITE(GMBUS3 + reg_offset, val);
I915_WRITE(GMBUS1 + reg_offset,