drm/i915/intel_i2c: handle zero-length writes
authorDaniel Kurtz <djkurtz@chromium.org>
Fri, 30 Mar 2012 11:46:36 +0000 (19:46 +0800)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Thu, 12 Apr 2012 19:14:06 +0000 (21:14 +0200)
commit26883c31b0799e76edf8f0ea8be48b64e09b2a7d
treea8ff83254d592500a16ed7843e103eb87316299d
parent3fdcf43192559f53305644d0c1e0f7dda398f091
drm/i915/intel_i2c: handle zero-length writes

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>
drivers/gpu/drm/i915/intel_i2c.c