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bh=EBi7fvn5PPMEBAZTEI/oc6Td7Rh4Sp2q4DZSjZkWn5Q=; b=HpNC6MszIjG0ugXiyEhvQs4v3jS2z7Yroa5mVAn5qc57Kia7NGiNVDk0PWzfpcWNnahBOI /YoO/HuOmSmTzr6+0nOn+OvXx+E5ngH/PbqMHYZO2j4Xx6n+nv3eo0PTeqLKO79zjJsESJ LWom8BhaSJ3Iab3vkrbhMHvkx/OMDlh9ESnLLl0wmIVPzHbOky4fGmOzRFxREzLdgkZpZM MKoiqwO1h/OuCIAlTMdD3uoImTAd6YyQBX27Ep8axqL71HvQ/aR7wzyLIvmu1MmEwWn6Sp u+xDLsPTc0nTBcbvNHeWCa8V6FQu5zyT3ba4QdbAkV+hux/PwofN4rrvRidlDg== Date: Mon, 10 Feb 2025 18:11:46 +0100 From: Luca Ceresoli To: Dmitry Baryshkov Cc: Simona Vetter , Inki Dae , Jagan Teki , Marek Szyprowski , Catalin Marinas , Will Deacon , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Daniel Thompson , Andrzej Hajda , Jonathan Corbet , Sam Ravnborg , Boris Brezillon , Nicolas Ferre , Alexandre Belloni , Claudiu Beznea , Jessica Zhang , Paul Kocialkowski , Maxime Ripard , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Thomas Zimmermann , David Airlie , =?UTF-8?B?SGVy?= =?UTF-8?B?dsOp?= Codina , Thomas Petazzoni , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Paul Kocialkowski Subject: Re: [PATCH v6 08/26] drm/bridge: panel: add a panel_bridge to every panel Message-ID: <20250210181146.232df79d@booty> In-Reply-To: References: <20250206-hotplug-drm-bridge-v6-0-9d6f2c9c3058@bootlin.com> <20250206-hotplug-drm-bridge-v6-8-9d6f2c9c3058@bootlin.com> <20250207095428.244f0f91@booty> Organization: Bootlin X-Mailer: Claws Mail 4.3.0 (GTK 3.24.43; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-GND-State: clean X-GND-Score: -100 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdefkeeigecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfitefpfffkpdcuggftfghnshhusghstghrihgsvgenuceurghilhhouhhtmecufedtudenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhepfffhvfevuffkjghfohfogggtgfesthejredtredtvdenucfhrhhomhepnfhutggrucevvghrvghsohhlihcuoehluhgtrgdrtggvrhgvshholhhisegsohhothhlihhnrdgtohhmqeenucggtffrrghtthgvrhhnpeeglefffefghefhtddvfeeufeeiveekgffgleekieduteekkeetvdehudekgfdvvdenucffohhmrghinhepsghoohhtlhhinhdrtghomhenucfkphepvdgrtddvmeeijedtmedvtddvtdemvggrtddumegsvgegudemleehvgejmeefgeefmeeludefvgenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpedvrgdtvdemieejtdemvddtvddtmegvrgdtudemsggvgedumeelhegvjeemfeegfeemledufegvpdhhvghlohepsghoohhthidpmhgrihhlfhhrohhmpehluhgtrgdrtggvrhgvshholhhisegsohhothhlihhnrdgtohhmpdhnsggprhgtphhtthhopeefjedprhgtphhtthhopegumhhithhrhidrsggrrhihshhhkhhovheslhhinhgrrhhordhorhhgpdhrtghpthhtohepshhimhhonhgrsehffhiflhhlrdgthhdprhgtphhtthhopehinhhkihdruggrvgesshgrmhhsuhhnghdrtghom hdprhgtphhtthhopehjrghgrghnsegrmhgrrhhulhgrshholhhuthhiohhnshdrtghomhdprhgtphhtthhopehmrdhsiiihphhrohifshhkihesshgrmhhsuhhnghdrtghomhdprhgtphhtthhopegtrghtrghlihhnrdhmrghrihhnrghssegrrhhmrdgtohhmpdhrtghpthhtohepfihilhhlsehkvghrnhgvlhdrohhrghdprhgtphhtthhopehshhgrfihnghhuoheskhgvrhhnvghlrdhorhhg X-GND-Sasl: luca.ceresoli@bootlin.com Hi Dmitry, On Fri, 7 Feb 2025 21:43:26 +0200 Dmitry Baryshkov wrote: > > > > @@ -1018,6 +1067,11 @@ struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev, > > > > { > > > > struct drm_bridge **ptr, *bridge; > > > > > > > > + if (panel->bridge) { > > > > + DRM_DEBUG("panel %s: returning existing bridge=%p", dev_name(dev), panel->bridge); > > > > + return panel->bridge; > > > > + } > > > > > > Shouldn't the rest of the function also be removed as you do in other > > > cases? > > > > Indeed it should. > > > > And even more, I now realize drm_panel_bridge_add_typed() should also > > become a simple 'return panel->bridge', like its devm and drmm > > variants, and its code, implementing the actual creation of a panel > > bridge, move to an internal function. Otherwise this patch is a bug: > > existing drivers which do call drm_panel_bridge_add_typed() would end > > up in having two panel_bridges for the same panel. > > > > I must say the process of developing this patch together with the > > hotplug work was "convoluted" to say the least, which probably explains > > why this got unnoticed so far. > > That's why I suggested to post this series separately - it saves you > from rebasing hotplug work on top. Yes, that's sure, but not keeping my hotplug patches on top of the panel_bridge ones makes it much harder for me to test on real hardware, so each way has pros and cons. However I might send only the panel_bridge patches at the next iteration. Luca -- Luca Ceresoli, Bootlin Embedded Linux and Kernel engineering https://bootlin.com