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

[Souza, Jose]

On Thu, 2018-04-26 at 15:51 -0700, Dhinakaran Pandiyan wrote:
> 
> 
> 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?

Oh thanks, I just fixed this in the next patch.

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

I'm not sure that hardware will send a interruption when it finish a
aux ch transaction that started by it self, that is why I'm going safe
here and just keep what is working for now.

> 
> > +		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;
> >  	}
> 
>