[PATCH 3/4] drm/dp/i2c: Update comments about common i2c over dp assumptions

[Ville Syrjälä]

On Fri, Apr 04, 2014 at 01:52:05PM -0400, Alex Deucher wrote:
> If you are using the common dp over i2c functionality, it is
> asumed that the aux transfer function does not modify the any
> of the msg structure other than the reply field.  Doing so
> breaks the logic in the common code.
> 
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Cc: Jani Nikula <jani.nikula at intel.com>
> Cc: Thierry Reding <treding at nvidia.com>

Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> ---
>  drivers/gpu/drm/drm_dp_helper.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 125f84d..7a8c091 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -577,7 +577,9 @@ static u32 drm_dp_i2c_functionality(struct i2c_adapter *adapter)
>  
>  /*
>   * Transfer a single I2C-over-AUX message and handle various error conditions,
> - * retrying the transaction as appropriate.
> + * retrying the transaction as appropriate.  It is assumed that the
> + * aux->transfer function does not modify anything in the msg other than the
> + * reply field.
>   */
>  static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
>  {
> -- 
> 1.8.3.1

-- 
Ville Syrjälä
Intel OTC