From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=193.142.43.55 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793696398; b=RAh3qyJJAAvuhBTjCmKwAbqGGTXMPSSzgqF8ioH3lq6rSk/RziEQLpxJWE0Tf+Qa6huP MSHuIUtgfOMyGpePrrMKjoYNyEeU109z1UfqeGuQqdTZbji0SJPldz6/ZtyqR3m2aeoqV rM9L/2DMLa2KpHiVUJaMBX9INW/WoVA7Ji2jkdwSTTj5r16TkO9iWNtBVJ0Kfwlk/kEEi Yz1GbXOi3CsBV3VLy9UqnduEjOOpSBGIOxgBt03SCWjUnT1WH0B22A10w4Bb+yVvltf1j +fhrI2Vz/bQPZvfrS5838fx/yHPS51NKkR66Vt45uqKufgMO5qz4IL98L7UuxGJvPPQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793696398; h=DMARC-Filter:Date:DKIM-Signature:DKIM-Signature:From:To:Cc:Subject: Message-ID:References:MIME-Version:Content-Type:Content-Disposition: In-Reply-To; bh=QD+CkWG5oyxTZO6V2pW1MZiGJv6VerTZJtv13Pu63rQ=; b=dvDGXSVDzmZBUoT8l6pp2Gf9P4SeLdJxfDR9hsqIUbUoEUKyBE5X8nZysXJ2miCtAPnN Ja5f48NKI2gdngM31e65y/N7fU3ZjiZu17oIC08qKTjkS1zknYS8tCQIVleOCxbJtkX7t M+H0F85boY6WKz6V0ufWKbFPm9LXoEbhk8yLq3tu8UdXprBAEUpmNfdpoxkS/iGJfuwUe loP1YeCQubcYutRHoJU3v3X1qAKU+Mj18QV29lQEgk8Hjd1itVrInLNdPk3a8djfNKC+1 XynYmTZDVtavX8tQ5FKNMWvsBivmvqdzRogLCF5X9j8Z22jQJJHwCcSt/KWvYAc35Bw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass header.d=linutronix.de header.i=@linutronix.de header.a=rsa-sha256 header.s=2020 header.b=TZQcwYgH; dkim=pass header.d=linutronix.de header.i=@linutronix.de header.a=ed25519-sha256 header.s=2020e header.b=BkGYvZPs; arc=none smtp.remote-ip=193.142.43.55 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1DB3B606A326 for ; Tue, 3 Nov 2026 08:59:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 1DB3B606A326 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=linutronix.de header.i=@linutronix.de header.a=rsa-sha256 header.s=2020 header.b=TZQcwYgH; dkim=pass header.d=linutronix.de header.i=@linutronix.de header.a=ed25519-sha256 header.s=2020e header.b=BkGYvZPs Date: Tue, 3 Nov 2026 09:59:49 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1793696391; 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=QD+CkWG5oyxTZO6V2pW1MZiGJv6VerTZJtv13Pu63rQ=; b=TZQcwYgHEkQKzBdxCYgoF4NlP5tocqsMMzriVFP/C1WqBZa09mv2OB2oqDSLHTxPBMi56Z xx9RC2sOxOvZZSB4ZGllg+wsv4OXMdYS/+VlZKuPXwAaLh3FZ3j8s0rKXV9sp9qYypwgjd vjhVej7+5lui3ST4QgKreOQJE8m53gvuNdZR/+OogXkO4p1wJShVaMIqzRlCCXOYe+pENX A41rGs9i7z2HuLPiMK8mvMrTjZLIIZsWw1XDlCq3MJduJg23yNiKC8twgnpIePHoKQe12N yZpcBoh3XX/1DZmq/iyUy4UxgODCgMvbhy3dVFVwJVMmYRKpW+PLCnbcDGN+/w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1793696391; 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=QD+CkWG5oyxTZO6V2pW1MZiGJv6VerTZJtv13Pu63rQ=; b=BkGYvZPsVd4OcDfywug6gYGoeGQK32t2wF3ew8Ol7bpFcJo40b4EnCyNA4YhhGdid6FuuP iS5opXFdm3oDP4CQ== From: Sebastian Andrzej Siewior To: Troy Mitchell Cc: Thomas Gleixner , Radu Rendec , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Clark Williams , Steven Rostedt , =?utf-8?B?QmrDtnJuIFTDtnBlbA==?= , Anup Patel , linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, linux-rt-devel@lists.linux.dev Subject: Re: [PATCH] irqchip/riscv-imsic: Synchronize remote state with IRQ work Message-ID: <20261103085949.HPHNwwhb@linutronix.de> References: <20261103-imsic-remote-sync-irqwork-v1-1-8b5c951fc62a@linux.dev> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20261103-imsic-remote-sync-irqwork-v1-1-8b5c951fc62a@linux.dev> On 2026-11-03 08:04:33 [+0000], Troy Mitchell wrote: > Without a real broadcast device, the tick code falls back to the hrtimer > based broadcast, which keeps one CPU's local timer running. Once the SoC > timer is registered it replaces the hrtimer broadcast, and every CPU may > stop its local timer in idle. > > On K3 the SoC timer interrupt goes through APLIC in MSI mode to IMSIC. > When the CPU owning it goes offline, the interrupt is moved to a CPU > that may already be idle with its local timer stopped. IMSIC leaves the > enable on the new target to a timer on that CPU, and that timer can only > fire through the broadcast interrupt, which is not enabled yet. The > system stalls. So the broadcast timer is moved on CPU which is idle and waking the CPU is done by a timer, which does not work if the CPU is idle. This makes sense. Sebastian