From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 E099B2E7622; Sat, 10 Oct 2026 19:52:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791661942; cv=none; b=GTgE/36d2ZyhGWact7aUKvwz0NWy6P9aAfUtRB4cCyB/kIMnx5YnID2wFIGM47rtXXdFYNq0M0sbTNFyRJ9xOnRQQ8dFIsAE45NZCUrYjhWiSnI7uaWt1Ox/1QdvOus8txvvlMn8bYwsVUFH8oEZTVQjI/Kijekc98STHSCO4CE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791661942; c=relaxed/simple; bh=z20t4eyrSZO9qnTBTHndz8FIcICFC1pVdp6SIPKlOw0=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=UWGKSgjcjOluDS0Hu2Pm3H0QVMPSwJTNYCHZ+1O0uULT1qN1XlQuBi/yBOiXkVRsEaCQtFFrDpCiu75HkbLcJf7luu69g4nKMJEpO5wYoKlEP2goTgtb4uMyFIIO7dPnNYqAHpzO9yR0ewYX0iBb0YjVvwfSIFpn7bSFC3Z8yns= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WaFBslUY; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WaFBslUY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 91D5C1F000FF; Sat, 10 Oct 2026 19:52:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791661940; bh=A4qxEAeQZjRwcbEDvQVSiP48ZIS0+/Hrzsm/TnGqMSY=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=WaFBslUYeqm6IckxmSEpB9nyUIyLCk6VWxIMCY73YWjGtZA9ythH3LeyX++I1y7aR lqPqvtWoWjX2Pw3Sc+vVZocxtMgVA17QML6o/lwLPstdtq0hKUruy/nQKEbnx0hnZK jIpZf2wZ7DOuY9YWDRjPc0AVFDK+WzepIWmw76a0VxN1LXngWCsyNMFGywBryzl/4G teO3n0IW+Le+fPIRVq9PKh8lJeVfmcPn91rGjTgShiYerSNCe9UM9mJx7hCYS7eiKQ FE2HnSmFIV4GSULngrSx9AtO1wFrE50+JkiTkv0AbcV26uAasTrIYR92w5tNTgcqQb z8YDlx176jZRw== From: Thomas Gleixner To: Eliav Farber , Talel Shenhar Cc: Radu Rendec , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Eliav Farber , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 8/8] irqchip/al-fic: add irq_set_affinity callback In-Reply-To: <20261008090058.38591-9-farbere@amazon.com> References: <20261008090058.38591-1-farbere@amazon.com> <20261008090058.38591-9-farbere@amazon.com> Date: Sat, 10 Oct 2026 21:52:16 +0200 Message-ID: <87jynpfi4v.ffs@fw13> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Thu, Oct 08 2026 at 09:00, Eliav Farber wrote: > The FIC aggregates up to 32 interrupt sources into a single parent GIC > SPI and has no per-child affinity control; affinity is determined by the > parent GIC SPI routing. > > irq_set_affinity() fails with -EINVAL when the target irqchip has no > irq_set_affinity callback, which prevents drivers that call it from > probing when their interrupt is routed through a FIC instance. Add an > irq_set_affinity callback that returns IRQ_SET_MASK_OK_DONE > unconditionally. > > Affinity requests cannot be forwarded to the parent GIC SPI, because it > may be shared by several FIC instances and changing its affinity for one > child would silently move all the others. A pr_warn_once() is emitted > when the requested affinity differs from the parent's current affinity, > giving visibility without failing the caller. No. That's a horrible hack and just pretends to solve a problem. We have the interrupt redirection infrastructure to handle that correctly. See fcc1d0dabd and subsequent commits. Thanks, tglx