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[94.141.168.29]) by smtp.gmail.com with ESMTPSA id r14sm3704681lfr.129.2022.01.31.08.38.14 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 31 Jan 2022 08:38:14 -0800 (PST) Message-ID: Date: Mon, 31 Jan 2022 19:38:13 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH] drm/bridge_connector: enable HPD by default if supported Content-Language: en-US To: Laurent Pinchart Cc: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Kieran Bingham , Jacopo Mondi , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org References: <20211225063151.2110878-1-nikita.yoush@cogentembedded.com> From: Nikita Yushchenko In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> Hotplug events reported by bridge drivers over drm_bridge_hpd_notify() >> get ignored unless somebody calls drm_bridge_hpd_enable(). When the >> connector for the bridge is bridge_connector, such a call is done from >> drm_bridge_connector_enable_hpd(). >> >> However drm_bridge_connector_enable_hpd() is never called on init paths, >> documentation suggests that it is intended for suspend/resume paths. > > Hmmmm... I'm in two minds about this. The problem description is > correct, but I wonder if HPD should be enabled unconditionally here, or > if this should be left to display drivers to control. > drivers/gpu/drm/imx/dcss/dcss-kms.c enables HPD manually at init time, > other drivers don't. > > It feels like this should be under control of the display controller > driver, but I can't think of a use case for not enabling HPD at init > time. Any second opinion from anyone ? Hi. Can we somehow move forward here?.. 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[94.141.168.29]) by smtp.gmail.com with ESMTPSA id r14sm3704681lfr.129.2022.01.31.08.38.14 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 31 Jan 2022 08:38:14 -0800 (PST) Message-ID: Date: Mon, 31 Jan 2022 19:38:13 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH] drm/bridge_connector: enable HPD by default if supported Content-Language: en-US To: Laurent Pinchart References: <20211225063151.2110878-1-nikita.yoush@cogentembedded.com> From: Nikita Yushchenko In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Mailman-Approved-At: Tue, 01 Feb 2022 09:01:14 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Thomas Zimmermann , David Airlie , linux-kernel@vger.kernel.org, Kieran Bingham , Jacopo Mondi , dri-devel@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" >> Hotplug events reported by bridge drivers over drm_bridge_hpd_notify() >> get ignored unless somebody calls drm_bridge_hpd_enable(). When the >> connector for the bridge is bridge_connector, such a call is done from >> drm_bridge_connector_enable_hpd(). >> >> However drm_bridge_connector_enable_hpd() is never called on init paths, >> documentation suggests that it is intended for suspend/resume paths. > > Hmmmm... I'm in two minds about this. The problem description is > correct, but I wonder if HPD should be enabled unconditionally here, or > if this should be left to display drivers to control. > drivers/gpu/drm/imx/dcss/dcss-kms.c enables HPD manually at init time, > other drivers don't. > > It feels like this should be under control of the display controller > driver, but I can't think of a use case for not enabling HPD at init > time. Any second opinion from anyone ? Hi. Can we somehow move forward here?..