From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [PATCH] drm/i915: preserve other DP_TEST_SINK bits. Date: Tue, 30 Sep 2014 22:36:42 +0200 Message-ID: <20140930203642.GE12343@phenom.ffwll.local> References: <1412029792-1992-1-git-send-email-rodrigo.vivi@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wi0-f171.google.com (mail-wi0-f171.google.com [209.85.212.171]) by gabe.freedesktop.org (Postfix) with ESMTP id 9A57D6EBCF for ; Tue, 30 Sep 2014 13:36:46 -0700 (PDT) Received: by mail-wi0-f171.google.com with SMTP id ho1so6762055wib.4 for ; Tue, 30 Sep 2014 13:36:45 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1412029792-1992-1-git-send-email-rodrigo.vivi@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Rodrigo Vivi Cc: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On Mon, Sep 29, 2014 at 06:29:52PM -0400, Rodrigo Vivi wrote: > Sink crc was implemented based on dp 1.1 spec that had all TEST_SINK bits > reserved reading all 0s. But when reviewing my latest changes on sink crc > Todd warned me that on new specs we have other valid bits on this reg that we > might want to preserve. > > Cc: Todd Previte > Signed-off-by: Rodrigo Vivi > --- > drivers/gpu/drm/i915/intel_dp.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > index b8699b0..7d5fa2f 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -3821,8 +3821,9 @@ int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc) > if (!(buf & DP_TEST_CRC_SUPPORTED)) > return -ENOTTY; > > + drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK, &buf); > if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_TEST_SINK, With this we no longer check the first aux transaction for errors, and maybe we should even check them all? -Daniel > - DP_TEST_SINK_START) < 0) > + buf | DP_TEST_SINK_START) < 0) > return -EIO; > > drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK_MISC, &buf); > @@ -3841,7 +3842,10 @@ int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc) > if (drm_dp_dpcd_read(&intel_dp->aux, DP_TEST_CRC_R_CR, crc, 6) < 0) > return -EIO; > > - drm_dp_dpcd_writeb(&intel_dp->aux, DP_TEST_SINK, 0); > + drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK, &buf); > + drm_dp_dpcd_writeb(&intel_dp->aux, DP_TEST_SINK, > + buf & ~DP_TEST_SINK_START); > + > return 0; > } > > -- > 1.9.3 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch