Re: [PATCH 1/2] drm/i915/dp: Print full branch/sink descriptor for all outputs

[Jani Nikula <jani.nikula@linux.intel.com>]

On Thu, 20 Oct 2016, Imre Deak <imre.deak@intel.com> wrote:
> Extend the branch/sink descriptor info with the missing device ID
> field and print this info for eDP and LSPCON connectors too.
>
> Signed-off-by: Imre Deak <imre.deak@intel.com>
> ---
>  drivers/gpu/drm/i915/intel_dp.c     | 83 +++++++++++++++----------------------
>  drivers/gpu/drm/i915/intel_drv.h    | 13 ++++++
>  drivers/gpu/drm/i915/intel_lspcon.c |  7 ++++
>  3 files changed, 53 insertions(+), 50 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 88f3b74..e90211e 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -1442,42 +1442,34 @@ static void intel_dp_print_rates(struct intel_dp *intel_dp)
>  	DRM_DEBUG_KMS("common rates: %s\n", str);
>  }
>  
> -static void intel_dp_print_hw_revision(struct intel_dp *intel_dp)
> +static bool intel_dp_is_branch(struct intel_dp *intel_dp)

Belongs in drm dp helpers.

>  {
> -	uint8_t rev;
> -	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_HW_REV, &rev, 1);
> -	if (len < 0)
> -		return;
> -
> -	DRM_DEBUG_KMS("sink hw revision: %d.%d\n", (rev & 0xf0) >> 4, rev & 0xf);
> +	return intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
> +	       DP_DWN_STRM_PORT_PRESENT;
>  }
>  
> -static void intel_dp_print_sw_revision(struct intel_dp *intel_dp)
> +bool
> +intel_dp_read_desc(struct intel_dp *intel_dp, struct intel_dp_desc *desc)
>  {
> -	uint8_t rev[2];
> -	int len;
> +	u32 base = intel_dp_is_branch(intel_dp) ? DP_BRANCH_OUI : DP_SINK_OUI;
>  
> -	if ((drm_debug & DRM_UT_KMS) == 0)
> -		return;
> +	return drm_dp_dpcd_read(&intel_dp->aux, base, desc, sizeof(*desc)) ==
> +	       sizeof(*desc);

Starting to read either branch or sink oui should be a standalone prep
change. I guess this should be done, although I've seen crappy devices
that report oui in wrong place...

> +}
>  
> -	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
> -	      DP_DWN_STRM_PORT_PRESENT))
> -		return;
> +void
> +intel_dp_print_desc(struct intel_dp *intel_dp, struct intel_dp_desc *desc)
> +{
> +	const char *dev_type = intel_dp_is_branch(intel_dp) ? "branch" : "sink";
> +	bool oui_sup = intel_dp->dpcd[DP_DOWN_STREAM_PORT_COUNT] &
> +		       DP_OUI_SUPPORT;
>  
> -	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]);
> +	DRM_DEBUG_KMS("DP %s: OUI %*phD%s dev-ID %.*s HW-rev %d.%d SW-rev %d.%d\n",
> +		      dev_type,
> +		      (int)sizeof(desc->oui), desc->oui, oui_sup ? "" : "(NS)",
> +		      (int)sizeof(desc->device_id), desc->device_id,
> +		      (desc->hw_rev & 0xf0) >> 4, (desc->hw_rev & 0xf),
> +		      desc->sw_major_rev, desc->sw_minor_rev);

I've been thinking about starting to print this stuff too. But again,
could be a standalone change.

>  }
>  
>  static int rate_to_index(int find, const int *rates)
> @@ -3519,6 +3511,13 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp)
>  	if (!intel_dp_read_dpcd(intel_dp))
>  		return false;
>  
> +	if (drm_debug & DRM_UT_KMS) {
> +		struct intel_dp_desc desc;
> +
> +		if (intel_dp_read_desc(intel_dp, &desc))
> +			intel_dp_print_desc(intel_dp, &desc);
> +	}

I *really* don't think we should do dpcd access conditional to drm
debugs. I smell heisenbugs just thinking about it.

> +
>  	if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11)
>  		dev_priv->no_aux_handshake = intel_dp->dpcd[DP_MAX_DOWNSPREAD] &
>  			DP_NO_AUX_HANDSHAKE_LINK_TRAINING;
> @@ -3621,23 +3620,6 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
>  	return true;
>  }
>  
> -static void
> -intel_dp_probe_oui(struct intel_dp *intel_dp)
> -{
> -	u8 buf[3];
> -
> -	if (!(intel_dp->dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
> -		return;
> -
> -	if (drm_dp_dpcd_read(&intel_dp->aux, DP_SINK_OUI, buf, 3) == 3)
> -		DRM_DEBUG_KMS("Sink OUI: %02hx%02hx%02hx\n",
> -			      buf[0], buf[1], buf[2]);
> -
> -	if (drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_OUI, buf, 3) == 3)
> -		DRM_DEBUG_KMS("Branch OUI: %02hx%02hx%02hx\n",
> -			      buf[0], buf[1], buf[2]);
> -}
> -
>  static bool
>  intel_dp_can_mst(struct intel_dp *intel_dp)
>  {
> @@ -4410,11 +4392,12 @@ intel_dp_long_pulse(struct intel_connector *intel_connector)
>  		      yesno(drm_dp_tps3_supported(intel_dp->dpcd)));
>  
>  	intel_dp_print_rates(intel_dp);
> +	if (drm_debug & DRM_UT_KMS) {
> +		struct intel_dp_desc desc;
>  
> -	intel_dp_probe_oui(intel_dp);
> -
> -	intel_dp_print_hw_revision(intel_dp);
> -	intel_dp_print_sw_revision(intel_dp);
> +		if (intel_dp_read_desc(intel_dp, &desc))
> +			intel_dp_print_desc(intel_dp, &desc);
> +	}

Ditto. I do like putting the desc reading into one place though.

>  
>  	intel_dp_configure_mst(intel_dp);
>  
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index c06a33e..a35e241 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -883,6 +883,14 @@ enum link_m_n_set {
>  	M2_N2
>  };
>  
> +struct intel_dp_desc {
> +	u8 oui[3];
> +	u8 device_id[6];
> +	u8 hw_rev;
> +	u8 sw_major_rev;
> +	u8 sw_minor_rev;
> +} __packed;
> +

I understand this, but makes me wonder about dp helpers vs. i915. I
guess we could add this for now.

>  struct intel_dp {
>  	i915_reg_t output_reg;
>  	i915_reg_t aux_ch_ctl_reg;
> @@ -1460,6 +1468,11 @@ static inline unsigned int intel_dp_unused_lane_mask(int lane_count)
>  	return ~((1 << lane_count) - 1) & 0xf;
>  }
>  
> +bool
> +intel_dp_read_desc(struct intel_dp *intel_dp, struct intel_dp_desc *desc);
> +void
> +intel_dp_print_desc(struct intel_dp *intel_dp, struct intel_dp_desc *desc);
> +
>  /* intel_dp_aux_backlight.c */
>  int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector);
>  
> diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c
> index 632149c..d2c8cb2 100644
> --- a/drivers/gpu/drm/i915/intel_lspcon.c
> +++ b/drivers/gpu/drm/i915/intel_lspcon.c
> @@ -131,6 +131,13 @@ bool lspcon_init(struct intel_digital_port *intel_dig_port)
>  		}
>  	}
>  
> +	if (drm_debug & DRM_UT_KMS) {
> +		struct intel_dp_desc desc;
> +
> +		if (intel_dp_read_desc(dp, &desc))
> +			intel_dp_print_desc(dp, &desc);
> +	}

Again, reads conditional to debugs is scary.

> +
>  	DRM_DEBUG_KMS("Success: LSPCON init\n");
>  	return true;
>  }

-- 
Jani Nikula, Intel Open Source Technology Center
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx