Re: [PATCH v9 37/39] drm/i915: Fix KBL HDCP2.2 encrypt status signalling

From: "C, Ramalingam" <ramalingam.c@intel.com>
To: Daniel Vetter <daniel@ffwll.ch>
Cc: daniel.vetter@ffwll.ch, intel-gfx@lists.freedesktop.org,
	dri-devel@lists.freedesktop.org, seanpaul@chromium.org,
	tomas.winkler@intel.com
Subject: Re: [PATCH v9 37/39] drm/i915: Fix KBL HDCP2.2 encrypt status signalling
Date: Wed, 19 Dec 2018 21:46:00 +0530	[thread overview]
Message-ID: <1277dde3-79ad-6669-e99a-57f0f301a763@intel.com> (raw)
In-Reply-To: <20181219154037.GO21184@phenom.ffwll.local>

On 12/19/2018 9:10 PM, Daniel Vetter wrote:
> On Thu, Dec 13, 2018 at 09:31:39AM +0530, Ramalingam C wrote:
>> Implement the required WA sequence for KBL to fix the
>> incorrect positioning of the window of oppurtunity and enc_en
>> signalling.
>>
>> Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
>> ---
>>   drivers/gpu/drm/i915/intel_hdcp.c | 29 +++++++++++++++++++++++++++++
>>   1 file changed, 29 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c
>> index 42327ed30903..2b9e1b6d0b1e 100644
>> --- a/drivers/gpu/drm/i915/intel_hdcp.c
>> +++ b/drivers/gpu/drm/i915/intel_hdcp.c
>> @@ -12,6 +12,7 @@
>>   #include <linux/i2c.h>
>>   #include <linux/random.h>
>>   #include <linux/component.h>
>> +#include <linux/delay.h>
>>   
>>   #include "intel_drv.h"
>>   #include "i915_reg.h"
>> @@ -20,6 +21,27 @@
>>   #define ENCRYPT_STATUS_CHANGE_TIMEOUT_MS	50
>>   #define HDCP2_LC_RETRY_CNT			3
>>   
>> +static void kbl_repositioning_enc_en_signal(struct intel_connector *connector)
>> +{
>> +	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
>> +	struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
>> +	struct intel_hdcp *hdcp = &connector->hdcp;
>> +	struct drm_crtc *crtc = connector->base.state->crtc;
>> +	struct intel_crtc *intel_crtc = container_of(crtc,
>> +						     struct intel_crtc, base);
>> +	u32 scanline;
>> +
>> +	for (;;) {
>> +		scanline = I915_READ(PIPEDSL(intel_crtc->pipe));
>> +		if (scanline > 100 && scanline < 200)
>> +			break;
>> +		usleep_range(25, 50);
>> +	}
>> +
>> +	hdcp->shim->toggle_signalling(intel_dig_port, false);
>> +	hdcp->shim->toggle_signalling(intel_dig_port, true);
>> +}
>> +
>>   static
>>   bool intel_hdcp_is_ksv_valid(u8 *ksv)
>>   {
>> @@ -1382,6 +1404,13 @@ static int hdcp2_enable_encryption(struct intel_connector *connector)
>>   	}
>>   
>>   	if (I915_READ(HDCP2_STATUS_DDI(port)) & LINK_AUTH_STATUS) {
>> +		/*
>> +		 * WA: To fix incorrect positioning of the window of
>> +		 * opportunity and enc_en signalling in KABYLAKE.
>> +		 */
>> +		if (IS_KABYLAKE(dev_priv) && hdcp->shim->toggle_signalling)
>> +			kbl_repositioning_enc_en_signal(connector);
> This is a bit a layering violation of the shim. I think it'd be better to
> push this into the toggle_signalling implementation, which you call right
> above. That can easily check this register too, and retry. That way the
> kbl flow is all in one place.

Yes, any way this is a fix for hdcp_signalling for kbl. I will do that.

-Ram

>
> Bspec is down for me, so can't check the w/a itself :-(
> -Daniel
>
>> +
>>   		/* Link is Authenticated. Now set for Encryption */
>>   		I915_WRITE(HDCP2_CTL_DDI(port),
>>   			   I915_READ(HDCP2_CTL_DDI(port)) |
>> -- 
>> 2.7.4
>>
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