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bh=4T0Z/wKoqLmnZWVx5qElF2JVZUpRD4o2zM/wrspldp0=; b=ZDorirDaJiVzEhZ+Dy5FPuY8TciEHIDL8biqP15QbS75l5K+mN/9vhPvUetmMwpkDRzfOQ WHb7+TFsKrBH1rRjrZR+jzIh2KfQOQ0Mq82vWl0vh8WPSNr8xmzHZiQ0V32deavtB6Ok9Y DOPJz+azWbHlfM+uSiIKZ4sA+6NuKrXe1ohvO3vS/ughrEkDvC5c7zCwTdep9PWkmfGdO1 QHICWKbWeAgfVett5jhC2c18sCM92MjX78cWfymdnXj2SRdFgpm8isir0uDWN+o+tVg+eY hQ2cniRepzW0GW0m+iIWQz54dDccAHp9LBbrgg4viHJtDjOCw6lwehfeLI81IQ== Date: Fri, 20 Jun 2025 10:33:53 +0200 From: Luca Ceresoli To: Anusha Srivatsa Cc: Neil Armstrong , Jessica Zhang , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Inki Dae , Jagan Teki , Marek Szyprowski , Andrzej Hajda , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Chen-Yu Tsai , Samuel Holland , Seung-Woo Kim , Kyungmin Park , Krzysztof Kozlowski , Alim Akhtar , Laurent Pinchart , Tomi Valkeinen , Kieran Bingham , Geert Uytterhoeven , Magnus Damm , Biju Das , Tomi Valkeinen , Alain Volmat , Raphael Gallais-Pou , Stefan Agner , Alison Wang , Linus Walleij , Thierry Reding , Mikko Perttunen , Jonathan Hunter , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-samsung-soc@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-tegra@vger.kernel.org Subject: Re: [PATCH v2 01/16] drm/panel: get/put panel reference in drm_panel_add/remove() Message-ID: <20250620103353.5b43b86f@booty> In-Reply-To: <20250619-b4-of_drm_find_panel_part1-v2-1-0df94aecc43d@redhat.com> References: <20250619-b4-of_drm_find_panel_part1-v2-0-0df94aecc43d@redhat.com> <20250619-b4-of_drm_find_panel_part1-v2-1-0df94aecc43d@redhat.com> Organization: Bootlin X-Mailer: Claws Mail 4.3.1 (GTK 3.24.49; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: linux-tegra@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: gggruggvucftvghtrhhoucdtuddrgeeffedrtddvgdejleefucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuifetpfffkfdpucggtfgfnhhsuhgsshgtrhhisggvnecuuegrihhlohhuthemuceftddunecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpeffhffvvefukfgjfhhoofggtgfgsehtjeertdertddvnecuhfhrohhmpefnuhgtrgcuvegvrhgvshholhhiuceolhhutggrrdgtvghrvghsohhlihessghoohhtlhhinhdrtghomheqnecuggftrfgrthhtvghrnhepgeelffefgfehhfdtvdefueefieevkefggfelkeeiudetkeektedvhedukefgvddvnecuffhomhgrihhnpegsohhothhlihhnrdgtohhmnecukfhppedvrgdtvdemieejtdemvddtvddtmegvrgdtudemsggvgedumeelhegvjeemfeegfeemledufegvnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehinhgvthepvdgrtddvmeeijedtmedvtddvtdemvggrtddumegsvgegudemleehvgejmeefgeefmeeludefvgdphhgvlhhopegsohhothihpdhmrghilhhfrhhomheplhhutggrrdgtvghrvghsohhlihessghoohhtlhhinhdrtghomhdpnhgspghrtghpthhtohepgeegpdhrtghpthhtoheprghsrhhivhgrthhssehrvgguhhgrthdrtghomhdprhgtphhtthhopehnvghilhdrrghrmhhsthhrohhngheslhhinhgrrhhordhorhhgpdhrtghpthhtohepjhgvshhsihgtrgdriihhrghnghesohhsshdrq hhurghltghomhhmrdgtohhmpdhrtghpthhtohepmhgrrghrthgvnhdrlhgrnhhkhhhorhhstheslhhinhhugidrihhnthgvlhdrtghomhdprhgtphhtthhopehmrhhiphgrrhgusehkvghrnhgvlhdrohhrghdprhgtphhtthhopehtiihimhhmvghrmhgrnhhnsehsuhhsvgdruggvpdhrtghpthhtoheprghirhhlihgvugesghhmrghilhdrtghomhdprhgtphhtthhopehsihhmohhnrgesfhhffihllhdrtghh Hello Anusha, On Thu, 19 Jun 2025 14:15:53 -0500 Anusha Srivatsa wrote: > Take the panel reference and put it back as required. > drm_panel_add() and drm_panel_remove() add a panel to > the global registry and removes a panel respectively. > Use get() and put() helpers to keep up with refcounting. > > Reviewed-by: Luca Ceresoli > Signed-off-by: Anusha Srivatsa This patch is good. I'd just point out that this must be applied only after all drivers have been converted to the the _alloc API, otherwise with the following sequence: panel = devm_kzalloc(); drm_panel_init(panel); drm_panel_add(panel); ... drm_panel_remove(panel); <----- at the drm_panel_remove() you'd have a warning: refcount_t: addition on 0; use-after-free. So, if all panel drivers are converted: Reviewed-by: Luca Ceresoli -- Luca Ceresoli, Bootlin Embedded Linux and Kernel engineering https://bootlin.com