Re: [PATCH] drm/i915/vlv: DP_SINK_COUNT is not reliable for valleyview platform.

From: Daniel Vetter <daniel@ffwll.ch>
To: Quanxian Wang <quanxian.wang@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH] drm/i915/vlv: DP_SINK_COUNT is not reliable for valleyview platform.
Date: Fri, 13 Jun 2014 09:16:29 +0200	[thread overview]
Message-ID: <20140613071629.GF5821@phenom.ffwll.local> (raw)
In-Reply-To: <1402642324-6260-1-git-send-email-quanxian.wang@intel.com>

On Fri, Jun 13, 2014 at 02:52:04PM +0800, Quanxian Wang wrote:
> DP connector will be disconnected after chvt to another console
> for 10 minutes or more on valleyview platform VTC1010.

This needs _much_ more detail, really.

Also it smells like we work around a sink issue, which means the correct
quirk is to use some sink id (like OUI), _not_ the platform. Since this
way you break all DP1.1+ stuff on vlv and if someone puts this panel onto
a different platform it still doesn't work.

Or I completely don't understand this at all.

Also, such a patch needs a full spec quote or a w/a citation or something
solid if it's a more generic issue.
-Daniel
> 
> Signed-off-by: Quanxian Wang <quanxian.wang@intel.com>
> ---
>  drivers/gpu/drm/i915/intel_dp.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 2688f6d..0d127a5 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -2942,6 +2942,7 @@ intel_dp_check_link_status(struct intel_dp *intel_dp)
>  static enum drm_connector_status
>  intel_dp_detect_dpcd(struct intel_dp *intel_dp)
>  {
> +	struct drm_device *dev = intel_dp_to_dev(intel_dp);
>  	uint8_t *dpcd = intel_dp->dpcd;
>  	uint8_t type;
>  
> @@ -2953,7 +2954,8 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp)
>  		return connector_status_connected;
>  
>  	/* If we're HPD-aware, SINK_COUNT changes dynamically */
> -	if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11 &&
> +	if (!IS_VALLEYVIEW(dev) &&
> +	    intel_dp->dpcd[DP_DPCD_REV] >= 0x11 &&
>  	    intel_dp->downstream_ports[0] & DP_DS_PORT_HPD) {
>  		uint8_t reg;
>  		if (!intel_dp_aux_native_read_retry(intel_dp, DP_SINK_COUNT,
> -- 
> 1.8.1.2
> 
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> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch