[Intel-gfx] [PATCH v2 7/9] drm/i915/dp: Move code to check if aux ch is busy to a function

[Dhinakaran Pandiyan]

On Wed, 2018-04-18 at 15:43 -0700, José Roberto de Souza wrote:
> This reduces the spaghetti that intel_dp_aux_xfer().
> 
> Moved doing less changes possible here, improvements to the new
> function in further patch.
> 
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> ---
> 
> New patch in this series.
> 
>  drivers/gpu/drm/i915/intel_dp.c | 52 +++++++++++++++++++++------------
>  1 file changed, 34 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 701963a192ee..a11465c62950 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -1062,6 +1062,38 @@ static uint32_t skl_get_aux_send_ctl(struct intel_dp *intel_dp,
>  	       DP_AUX_CH_CTL_SYNC_PULSE_SKL(32);
>  }
>  
> +static bool intel_dp_aux_is_busy(struct intel_dp *intel_dp)
> +{
> +	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
> +	struct drm_i915_private *dev_priv =
> +			to_i915(intel_dig_port->base.base.dev);
> +	i915_reg_t ch_ctl;
> +	uint32_t status;
> +	int try;
> +
> +	ch_ctl = intel_dp->aux_ch_ctl_reg(intel_dp);
> +
> +	for (try = 0; try < 3; try++) {
> +		status = I915_READ_NOTRACE(ch_ctl);
> +		if ((status & DP_AUX_CH_CTL_SEND_BUSY) == 0)
> +			break;

Did you mean to return false here?

Anyway, this code here looks very similar to intel_dp_aux_wait_done().
Might be worth checking if it can be reused.

> +		msleep(1);
> +	}
> +
> +	if (try == 3) {
> +		static u32 last_status = -1;
> +		const u32 status = I915_READ(ch_ctl);
> +
> +		if (status != last_status) {
> +			WARN(1, "dp_aux_ch not started status 0x%08x\n",
> +			     status);
> +			last_status = status;
> +		}
> +	}
> +
> +	return true;
> +}
> +
>  static int
>  intel_dp_aux_xfer(struct intel_dp *intel_dp,
>  		  const uint8_t *send, int send_bytes,
> @@ -1074,7 +1106,7 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
>  	i915_reg_t ch_ctl, ch_data[5];
>  	uint32_t aux_clock_divider;
>  	int i, ret, recv_bytes;
> -	uint32_t status;
> +	uint32_t status = 0;
>  	int try, clock = 0;
>  	bool has_aux_irq = HAS_AUX_IRQ(dev_priv);
>  	bool vdd;
> @@ -1102,23 +1134,7 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
>  	intel_dp_check_edp(intel_dp);
>  
>  	/* Try to wait for any previous AUX channel activity */
> -	for (try = 0; try < 3; try++) {
> -		status = I915_READ_NOTRACE(ch_ctl);
> -		if ((status & DP_AUX_CH_CTL_SEND_BUSY) == 0)
> -			break;
> -		msleep(1);
> -	}
> -
> -	if (try == 3) {
> -		static u32 last_status = -1;
> -		const u32 status = I915_READ(ch_ctl);
> -
> -		if (status != last_status) {
> -			WARN(1, "dp_aux_ch not started status 0x%08x\n",
> -			     status);
> -			last_status = status;
> -		}
> -
> +	if (intel_dp_aux_is_busy(intel_dp)) {
>  		ret = -EBUSY;
>  		goto out;
>  	}