[PATCH v8 08/12] drm/i915: Read DP branch device SW revision

[Kahola, Mika]

> -----Original Message-----
> From: Jim Bride [mailto:jim.bride at linux.intel.com]
> Sent: Thursday, September 8, 2016 12:20 AM
> To: Kahola, Mika <mika.kahola at intel.com>
> Cc: intel-gfx at lists.freedesktop.org; dri-devel at lists.freedesktop.org;
> ville.syrjala at linux.intel.com; daniel.vetter at ffwll.ch
> Subject: Re: [PATCH v8 08/12] drm/i915: Read DP branch device SW revision
> 
> On Wed, Aug 17, 2016 at 01:49:44PM +0300, Mika Kahola wrote:
> > SW revision is mandatory field for DisplayPort branch devices. This is
> > defined in DPCD register field 0x50A.
> 
> To be precise, the revision info is in 0x50A and 0x50B. Since both the major
> and minor versions are called out separately in the DP spec it's probably
> worth mentioning both addresses in the commit message.
You're right. I will update the commit message to be more exact.

> 
> >
> > v2: move drm_dp_ds_revision structure to be part of
> >     drm_dp_link structure (Daniel)
> > v3: remove dependency to drm_dp_helper but instead parse
> >     DPCD and print SW revision info to dmesg (Ville)
> >
> > Signed-off-by: Mika Kahola <mika.kahola at intel.com>
> 
> With the commit message change requested above, this is:
> 
> Reviewed-by: Jim Bride <jim.bride at linux.intel.com>
> 
> > ---
> >  drivers/gpu/drm/i915/intel_dp.c | 20 ++++++++++++++++++++
> >  include/drm/drm_dp_helper.h     |  1 +
> >  2 files changed, 21 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c
> > b/drivers/gpu/drm/i915/intel_dp.c index 9aebdf6..91ffb79 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -1438,6 +1438,25 @@ static void intel_dp_print_hw_revision(struct
> intel_dp *intel_dp)
> >  	DRM_DEBUG_KMS("sink hw revision: %d.%d\n", (rev & 0xf0) >> 4,
> rev &
> > 0xf);  }
> >
> > +static void intel_dp_print_sw_revision(struct intel_dp *intel_dp) {
> > +	uint8_t rev[2];
> > +	int len;
> > +
> > +	if ((drm_debug & DRM_UT_KMS) == 0)
> > +		return;
> > +
> > +	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
> > +	      DP_DWN_STRM_PORT_PRESENT))
> > +		return;
> > +
> > +	len = drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_SW_REV,
> &rev, 2);
> > +	if (len < 0)
> > +		return;
> > +
> > +	DRM_DEBUG_KMS("sink sw revision: %d.%d\n", rev[0], rev[1]); }
> > +
> >  static int rate_to_index(int find, const int *rates)  {
> >  	int i = 0;
> > @@ -4302,6 +4321,7 @@ intel_dp_long_pulse(struct intel_connector
> *intel_connector)
> >  	intel_dp_probe_oui(intel_dp);
> >
> >  	intel_dp_print_hw_revision(intel_dp);
> > +	intel_dp_print_sw_revision(intel_dp);
> >
> >  	intel_dp_configure_mst(intel_dp);
> >
> > diff --git a/include/drm/drm_dp_helper.h
> b/include/drm/drm_dp_helper.h
> > index 19ac599..215202f 100644
> > --- a/include/drm/drm_dp_helper.h
> > +++ b/include/drm/drm_dp_helper.h
> > @@ -447,6 +447,7 @@
> >  #define DP_BRANCH_OUI			    0x500
> >  #define DP_BRANCH_ID                        0x503
> >  #define DP_BRANCH_HW_REV                    0x509
> > +#define DP_BRANCH_SW_REV                    0x50A
> >
> >  #define DP_SET_POWER                        0x600
> >  # define DP_SET_POWER_D0                    0x1
> > --
> > 1.9.1