[Intel-gfx] [PATCH 2/5] drm/i915: read full receiver capability field during DP hot plug

[Jesse Barnes]

On Thu, 22 Sep 2011 09:41:01 +0100
Chris Wilson <chris at chris-wilson.co.uk> wrote:

> On Thu, 22 Sep 2011 11:15:58 +0530, Jesse Barnes
> <jbarnes at virtuousgeek.org> wrote:
> > Read link status first, followed by the full DPCD receiver cap field
> > rather than just the first 8 bytes.
> > 
> > Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
> > ---
> >  drivers/gpu/drm/i915/i915_irq.c |    2 ++
> >  drivers/gpu/drm/i915/intel_dp.c |    4 ++--
> >  2 files changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_irq.c
> > b/drivers/gpu/drm/i915/i915_irq.c index 02f96fd..80b49cc 100644
> > --- a/drivers/gpu/drm/i915/i915_irq.c
> > +++ b/drivers/gpu/drm/i915/i915_irq.c
> > @@ -530,6 +530,7 @@ static irqreturn_t
> > ivybridge_irq_handler(DRM_IRQ_ARGS) if (pch_iir &
> > SDE_HOTPLUG_MASK_CPT) queue_work(dev_priv->wq,
> > &dev_priv->hotplug_work); pch_irq_handler(dev);
> > +		I915_WRITE(PCH_PORT_HOTPLUG,
> > I915_READ(PCH_PORT_HOTPLUG)); }
> >  
> >  	if (pm_iir & GEN6_PM_DEFERRED_EVENTS) {
> > @@ -629,6 +630,7 @@ static irqreturn_t
> > ironlake_irq_handler(DRM_IRQ_ARGS) if (pch_iir & hotplug_mask)
> >  			queue_work(dev_priv->wq,
> > &dev_priv->hotplug_work); pch_irq_handler(dev);
> > +		I915_WRITE(PCH_PORT_HOTPLUG,
> > I915_READ(PCH_PORT_HOTPLUG)); }
> 
> This is a seperate chunk to the commit message.

Damnit, git commit -a should ask "do you really mean it?".

> >  
> >  	if (de_iir & DE_PCU_EVENT) {
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c
> > b/drivers/gpu/drm/i915/intel_dp.c index 0feae90..01848f9 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -36,7 +36,7 @@
> >  #include "i915_drv.h"
> >  #include "drm_dp_helper.h"
> >  
> > -
> > +#define DP_RECEIVER_CAP_SIZE	0xf
> >  #define DP_LINK_STATUS_SIZE	6
> >  #define DP_LINK_CHECK_TIMEOUT	(10 * 1000)
> >  
> > @@ -53,7 +53,7 @@ struct intel_dp {
> >  	int dpms_mode;
> >  	uint8_t link_bw;
> >  	uint8_t lane_count;
> > -	uint8_t dpcd[8];
> > +	uint8_t dpcd[DP_RECEIVER_CAP_SIZE];
> >  	struct i2c_adapter adapter;
> >  	struct i2c_algo_dp_aux_data algo;
> >  	bool is_pch_edp;
> 
> So I'm not seeing the quick check followed by the full read as
> described.

Increasing the DPCD size here increases the read size to include the
full receiver caps field.  We already read the link status at hot plug
time, so the commit message is a little misleading.  The main fix here
is to read the full caps field rather than just the first 8 bytes.

Jesse