[Intel-gfx] [PATCH v4 1/2] drm/i915/dp: Helper for checking DDI_BUF_CTL Idle status

[Ville Syrjälä]

On Tue, Jun 30, 2020 at 01:49:22PM -0700, Manasi Navare wrote:
> On Tue, Jun 30, 2020 at 06:30:16PM +0300, Ville Syrjälä wrote:
> > On Fri, Jun 26, 2020 at 04:26:40PM -0700, Manasi Navare wrote:
> > > Modify the helper to add a fixed delay or poll with timeout
> > > based on platform specification to check for either Idle bit
> > > set (DDI_BUF_CTL is idle for disable case)
> > > 
> > > v3:
> > > * Change the timeout to 16usecs (Ville)
> > > v2:
> > > * Use 2 separate functions or idle and active (Ville)
> > 
> > Missing changelog? Did somehting change?
> >
> 
> No its a v3 for thsi patch, but patch 2/2 is a v4 so published
> both patches with a v4,

Doh. The changelog is backwards so didn't even notice.

> 
> does this now look good with v3, timeout changed to 16 usecs?
> 
> Manasi
>  
> > > 
> > > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > Cc: Imre Deak <imre.deak at intel.com>
> > > Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/display/intel_ddi.c | 17 ++++++++---------
> > >  1 file changed, 8 insertions(+), 9 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> > > index 884b507c5f55..052a74625a61 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> > > @@ -1184,16 +1184,15 @@ static void intel_prepare_hdmi_ddi_buffers(struct intel_encoder *encoder,
> > >  static void intel_wait_ddi_buf_idle(struct drm_i915_private *dev_priv,
> > >  				    enum port port)
> > >  {
> > > -	i915_reg_t reg = DDI_BUF_CTL(port);
> > > -	int i;
> > > -
> > > -	for (i = 0; i < 16; i++) {
> > > -		udelay(1);
> > > -		if (intel_de_read(dev_priv, reg) & DDI_BUF_IS_IDLE)
> > > -			return;
> > > +	if (IS_BROXTON(dev_priv)) {
> > > +		udelay(16);
> > > +		return;
> > >  	}
> > > -	drm_err(&dev_priv->drm, "Timeout waiting for DDI BUF %c idle bit\n",
> > > -		port_name(port));
> > > +
> > > +	if (wait_for_us((intel_de_read(dev_priv, DDI_BUF_CTL(port)) &
> > > +			 DDI_BUF_IS_IDLE), 16))
> > > +		drm_err(&dev_priv->drm, "Timeout waiting for DDI BUF %c to get idle\n",
> > > +			port_name(port));
> > >  }
> > >  
> > >  static u32 hsw_pll_to_ddi_pll_sel(const struct intel_shared_dpll *pll)
> > > -- 
> > > 2.19.1
> > 
> > -- 
> > Ville Syrjälä
> > Intel

-- 
Ville Syrjälä
Intel