From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay5-d.mail.gandi.net (relay5-d.mail.gandi.net [217.70.183.197]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6A70C4A33 for ; Mon, 8 Sep 2025 13:57:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.197 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757339822; cv=none; b=tpNJ+pdg/a7MJIcPx0bdkLhvKdQc8MXh/NhAxWqTqrmRJHN3xRhiFmbl4Qqeb82w1FOvIljuVLlxD4jkqDJmHsSO4Xh2cn5B0AEc9n2r90SXiYA9Y8wQwlCqZuOpN44CqiOQBXVGIYyAbGQA1jNxoXE6lqk+GUqhtbsGj+C4Kv8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757339822; c=relaxed/simple; bh=kCV30dBfGGj+qizPbAVyMrrqYG8WkMODhk9dwkcURxw=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=VwRcytS9pxjN4yzct1k16FE2wNbpaH9BMGQXLGHSAOG+3jCBlVRsGg8fVYwzMLWAetEt60FHe0RcmuayMczis1hPAU9J5dhd5aLjNchUtZna7UfS/eFAAwxEiFdnDgSRiX5vu0PGyOwjF95CgWwCkyEgN/jL3n+HdaCqmiGbTM0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=xenomai.org; spf=pass smtp.mailfrom=xenomai.org; dkim=pass (2048-bit key) header.d=xenomai.org header.i=@xenomai.org header.b=l9Q4Agqf; arc=none smtp.client-ip=217.70.183.197 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=xenomai.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=xenomai.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=xenomai.org header.i=@xenomai.org header.b="l9Q4Agqf" Received: by mail.gandi.net (Postfix) with ESMTPSA id C26CA432D6; Mon, 8 Sep 2025 13:56:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=xenomai.org; s=gm1; t=1757339818; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=auLAxrT2TSSfFM4CsXv9w6nKv5CEnlRZZfJ51K0pois=; b=l9Q4Agqfph4KgiWgdznI9jnMkscqoeFMK/cfa+sBEHvn3FL1YJuP1TNpaj+CxHkF3Udbnr tFDdCtTs/I5kxIobOBxecjaKszPvLe4x+MNQE1Xx9z8wDK2LRw3Zv+Ye7UtsLWe/pR0Brl 1p450KZG3KLFSfZ9KNl1CChgQKqFuhY4L7CuSkMw3XbX8uKw+l6Z8vryRuVC4zXbGBM8gG NHiqFOm/cl/5OAsbbRVnbvRehuCa8TjVjI36sCoyVdeDSphh7dBuKIhaqYNPHTN6pUiO89 W1WPbloUuPMomVVpgafAFRFS2JdbUMxqgO/SMWClwKMmqZOADxWYfBwOrI/i3w== From: Philippe Gerum To: Florian Bezdeka Cc: xenomai@lists.linux.dev Subject: Re: [RFC Dovetail 6.16]: Lockdep warning, IRQ while holding pci_config_lock In-Reply-To: <87a53582y0.fsf@xenomai.org> (Philippe Gerum's message of "Mon, 08 Sep 2025 15:54:31 +0200") References: <2d7bbdc839cb0f78ddb979b35d491a8f4fb9d0c8.camel@siemens.com> <87a53582y0.fsf@xenomai.org> User-Agent: mu4e 1.12.12; emacs 30.2 Date: Mon, 08 Sep 2025 15:56:58 +0200 Message-ID: <871poh82tx.fsf@xenomai.org> Precedence: bulk X-Mailing-List: xenomai@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-GND-State: clean X-GND-Score: -100 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeeffedrtdeggddujeejudcutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfitefpfffkpdcuggftfghnshhusghstghrihgsvgenuceurghilhhouhhtmecufedtudenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephffvvefujghffgffkfggtgesthdtredttdertdenucfhrhhomheprfhhihhlihhpphgvucfivghruhhmuceorhhpmhesgigvnhhomhgrihdrohhrgheqnecuggftrfgrthhtvghrnhepvdelhfdvheekudehveelgeeitdeujefgkefhieejfedvieejkeegiefgjefhkeegnecukfhppedvrgdtudemvgdtrgemudelsgemfegtugdtmeelkeelrgemhegtgegsmegsjehffhemsggrfhenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpedvrgdtudemvgdtrgemudelsgemfegtugdtmeelkeelrgemhegtgegsmegsjehffhemsggrfhdphhgvlhhopehphihrohdpmhgrihhlfhhrohhmpehrphhmseigvghnohhmrghirdhorhhgpdhnsggprhgtphhtthhopedvpdhrtghpthhtohepgigvnhhomhgriheslhhishhtshdrlhhinhhugidruggvvhdprhgtphhtthhopehflhhorhhirghnrdgsvgiiuggvkhgrsehsihgvmhgvnhhsrdgtohhm X-GND-Sasl: rpm@xenomai.org Philippe Gerum writes: > Florian Bezdeka writes: > >> Hi Philippe, >> >> from time to time I can see the following lockdep warning when testing >> on qemu. >> >> I'm not sure if my interpretation is correct. Should we convert >> pci_config_lock into a hard_spin_lock_t? >> > > No, we can't convert this lock. This would be a massive trauma, both > with respect to the PCI locking model and latency figures. Besides, that would not fix the core issue since the deadlock would still be there, and lockdep would still notice anyway (Dovetail locks are lockdep-tracked too). -- Philippe.