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AJvYcCUWlwhoVHdW6MRdUWWY+Z+JVI72Jd0IIX5lrm0s07XIXNzk+izkGva7rSr98iNDoHvrtGZ9zOCeryVxnLU0@vger.kernel.org X-Gm-Message-State: AOJu0Yx++bPcA0bxrvupUm81SQDYNawGj/6V62pi2wOoGPB7wKs8qjLI 0qzYjfdm2exh0FjMm4Vo3W8c8atI13Fqf6nCj95paDY6+1SYEFpZ3AuWU9XJ7fM= X-Gm-Gg: ASbGncu7V8D+AWh3ZoetkljZvv0p3rntO2gtX8JtY7P3YP/vmyvvNdso+JRm7Z8KlKe Nl+FY5jCWoVPxAkfR5B2Sr8ZJFh5VCdWC3Phlcv3gf6FfqVGRmN1NL2JoJq+bpZDU5zsq+Rygzm a7nyRoRmBDMHKPHUHiOWNqgYu6SHchC2lehgy+o4fbgs9LnRW+3oLKrG5OqbsITuE/FdpQCydtn 1jwIEza+j5hycs8u5tkVs1fPeZv43aqRT/m2TjSdTeMzNDAYPI4APw= X-Google-Smtp-Source: AGHT+IFZfJfwssLNpBYM5MjiXFRSaZImZ4dWDIr4RYjQoPZfimRRPYITmNGGjTmVo8KU+9ieJp1Ivg== X-Received: by 2002:a05:600c:6b6f:b0:436:e86e:e4ab with SMTP id 5b1f17b1804b1-436e86ee529mr33625975e9.30.1736424863901; Thu, 09 Jan 2025 04:14:23 -0800 (PST) Received: from linaro.org ([86.121.162.10]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-436e2da6401sm53853955e9.2.2025.01.09.04.14.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Jan 2025 04:14:23 -0800 (PST) Date: Thu, 9 Jan 2025 14:14:21 +0200 From: Abel Vesa To: Bjorn Andersson Cc: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Karol Herbst , Lyude Paul , Danilo Krummrich , Jani Nikula , Rodrigo Vivi , Joonas Lahtinen , Tvrtko Ursulin , Rob Clark , Abhinav Kumar , Dmitry Baryshkov , Sean Paul , Marijn Suijten , Konrad Dybcio , Johan Hovold , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, nouveau@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org, Johan Hovold Subject: Re: [PATCH v4 1/4] drm/dp: Add helper to set LTTPRs in transparent mode Message-ID: References: <20250108-drm-dp-msm-add-lttpr-transparent-mode-set-v4-0-918949bc2e3a@linaro.org> <20250108-drm-dp-msm-add-lttpr-transparent-mode-set-v4-1-918949bc2e3a@linaro.org> Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On 25-01-08 16:17:47, Bjorn Andersson wrote: > On Wed, Jan 08, 2025 at 04:31:43PM +0200, Abel Vesa wrote: > > According to the DisplayPort standard, LTTPRs have two operating > > modes: > > - non-transparent - it replies to DPCD LTTPR field specific AUX > > requests, while passes through all other AUX requests > > - transparent - it passes through all AUX requests. > > > > Switching between this two modes is done by the DPTX by issuing > > an AUX write to the DPCD PHY_REPEATER_MODE register. > > > > Add a generic helper that allows switching between these modes. > > > > Also add a generic wrapper for the helper that handles the explicit > > disabling of non-transparent mode and its disable->enable sequence > > mentioned in the DP Standard v2.0 section 3.6.6.1. Do this in order > > to move this handling out of the vendor specific driver implementation > > into the generic framework. > > > > Tested-by: Johan Hovold > > Reviewed-by: Dmitry Baryshkov > > Reviewed-by: Johan Hovold > > Signed-off-by: Abel Vesa > > --- > > drivers/gpu/drm/display/drm_dp_helper.c | 62 +++++++++++++++++++++++++++++++++ > > include/drm/display/drm_dp_helper.h | 2 ++ > > 2 files changed, 64 insertions(+) > > > > diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c > > index da3c8521a7fa7d3c9761377363cdd4b44ab1106e..fa7eff94d408718a1762834597f0cd51376d2596 100644 > > --- a/drivers/gpu/drm/display/drm_dp_helper.c > > +++ b/drivers/gpu/drm/display/drm_dp_helper.c > > @@ -2817,6 +2817,68 @@ int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) > > } > > EXPORT_SYMBOL(drm_dp_lttpr_max_link_rate); > > > > +/** > > + * drm_dp_lttpr_set_transparent_mode - set the LTTPR in transparent mode > > kernel-doc functions should have () suffix Yes, will add. > > > + * @aux: DisplayPort AUX channel > > + * @enable: Enable or disable transparent mode > > + * > > + * Returns 0 on success or a negative error code on failure. > > And this should be "Return: ...". Will fix as well. > > > + */ > > +int drm_dp_lttpr_set_transparent_mode(struct drm_dp_aux *aux, bool enable) > > +{ > > + u8 val = enable ? DP_PHY_REPEATER_MODE_TRANSPARENT : > > + DP_PHY_REPEATER_MODE_NON_TRANSPARENT; > > + int ret = drm_dp_dpcd_writeb(aux, DP_PHY_REPEATER_MODE, val); > > + > > + if (ret < 0) > > + return ret; > > + > > + return (ret == 1) ? 0 : -EIO; > > +} > > +EXPORT_SYMBOL(drm_dp_lttpr_set_transparent_mode); > > + > > +/** > > + * drm_dp_lttpr_init - init LTTPR transparency mode according to DP standard > > + * > > Documentation also explicitly says not to leave a blank line here... Will drop the blank line. > > Regards, > Bjorn > Thanks for reviewing! Abel