From a6c8aff022d4d06e4b41455ae9b2a5d3d503bf76 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Mon, 7 Apr 2014 12:37:25 +0300 Subject: drm/i915: support address only i2c-over-aux transactions To support bare address requests used by the drm dp helpers. Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/intel_dp.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index a0dad1a2f819..d2a55884ad52 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -575,7 +575,8 @@ out: return ret; } -#define HEADER_SIZE 4 +#define BARE_ADDRESS_SIZE 3 +#define HEADER_SIZE (BARE_ADDRESS_SIZE + 1) static ssize_t intel_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) { @@ -592,7 +593,7 @@ intel_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) switch (msg->request & ~DP_AUX_I2C_MOT) { case DP_AUX_NATIVE_WRITE: case DP_AUX_I2C_WRITE: - txsize = HEADER_SIZE + msg->size; + txsize = msg->size ? HEADER_SIZE + msg->size : BARE_ADDRESS_SIZE; rxsize = 1; if (WARN_ON(txsize > 20)) @@ -611,7 +612,7 @@ intel_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) case DP_AUX_NATIVE_READ: case DP_AUX_I2C_READ: - txsize = HEADER_SIZE; + txsize = msg->size ? HEADER_SIZE : BARE_ADDRESS_SIZE; rxsize = msg->size + 1; if (WARN_ON(rxsize > 20)) -- cgit v1.2.3