From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BD2C0C43458 for ; Mon, 6 Jul 2026 23:21:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:References:Cc:To :From:Subject:Message-Id:Date:Content-Type:Content-Transfer-Encoding: Mime-Version:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=OEZrGANo2cEZWsDxSQlyGeYA6D2OMj2sQBUWO+CdYtI=; b=tljD0dcT4mEvMjzAfGPn9Hg3It zuQ1pnjZBMVbgqP4G3FEcBmEShCxn0mMAcKbfZ9ipxll4t8yG+hH9YZ+XDyENH8coPjKq96q21tNR EL/W0J6lBZybCVcUUn2vV2KP8myCOEoK/faWnX8wvasF5gvhNeIU6Xb7mBkLE6I5F1+ICkExLoyvD DtFWxPvROxMY0XGiRUJN9m2KI0Gv9msi90n9Gi+d4SAQHKDa5OjnBYgUqlbTay/dMyLAe2UsNoADX Tk2tah/9tGVQSL/lr99Q2A7XJQRDwe0O6fr+Y30V318lWQcTLubnsYyaxoTg/A8XBLckhCLnkvpGL btjAEJfQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wgscp-0000000Dmu6-3m5U; Mon, 06 Jul 2026 23:21:19 +0000 Received: from smtp.forwardemail.net ([121.127.44.73]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wgscn-0000000DmtS-176W for linux-arm-kernel@lists.infradead.org; Mon, 06 Jul 2026 23:21:18 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ubuntu.com; h=In-Reply-To: References: Cc: To: From: Subject: Message-Id: Date: Content-Type: Content-Transfer-Encoding: Mime-Version; q=dns/txt; s=fe-953a8a3ca9; t=1783380075; bh=OEZrGANo2cEZWsDxSQlyGeYA6D2OMj2sQBUWO+CdYtI=; b=BYbErYb0mJcGop6hON/c1ypQsc1YUviguOFUiG72nsQqWg/ILyLMbLblu0OF8yW5+SSBvKtRn Pkb4sWseMgEC9/cKJc/z7zopV0BA4IohN1NZxYEecLoqUQSKmJXZcQckpvPqzrvmZn4yeDKa9Mv zsISQP6zJSdNXUjgpUbn+/deA2Ht007vSOnyEFC/hEo9HgijenlEBeAxJFYCcrzaNnXkuSelM2i krxBLT8UUuzykMhuGZgKS84BHzEbSXfiPbFqhlxvetsMrU93IYNJ1QlasqOYvLyXBDU+p7b3AsB kJlU/moR4j7IC4PNZHV/Y9w/ZG/ZE6G+oheXQJ1wUOfQ== X-Forward-Email-ID: 6a4c3867ebac8711c86b79d5 X-Forward-Email-Sender: rfc822; jpeisach@ubuntu.com, smtp.forwardemail.net, 121.127.44.73 X-Forward-Email-Version: 2.9.7 X-Forward-Email-Website: https://forwardemail.net X-Complaints-To: abuse@forwardemail.net X-Report-Abuse: abuse@forwardemail.net X-Report-Abuse-To: abuse@forwardemail.net Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8; format=Flowed Date: Mon, 06 Jul 2026 19:21:09 -0400 Message-Id: Subject: Re: [PATCH] arch: arm64: add early_param idle= From: "Joshua Peisach" To: "Yureka Lilian" , "Jonathan Corbet" , "Shuah Khan" , "Catalin Marinas" , "Will Deacon" Cc: , , , X-Mailer: aerc 0.21.0 References: <20260705-arm64-idle-param-v1-1-7454249f473f@cyberchaos.dev> In-Reply-To: <20260705-arm64-idle-param-v1-1-7454249f473f@cyberchaos.dev> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260706_162117_656311_990176A9 X-CRM114-Status: GOOD ( 10.25 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sun Jul 5, 2026 at 6:02 AM EDT, Yureka Lilian wrote: > + > +enum idle_mode idle =3D WFI; > + > +/* User can over-ride above with "idle=3D" in cmdline */ > +static int __init setup_idle(char *s) > +{ > + if (!s) > + return -1; > + else if (!strcmp(s, "wfi")) > + idle =3D WFI; > + else if (!strcmp(s, "yield")) > + idle =3D YIELD; > + else if (!strcmp(s, "nop")) > + idle =3D NOP; > + else > + return -1; > + > + return 0; > +} > +early_param("idle", setup_idle); > + > /* > * cpu_do_idle() > * > @@ -26,8 +48,13 @@ void __cpuidle cpu_do_idle(void) > =20 > arm_cpuidle_save_irq_context(&context); > =20 > - dsb(sy); > - wfi(); > + if (likely(idle =3D=3D WFI)) { > + dsb(sy); > + wfi(); > + } else if (idle =3D=3D YIELD) { > + dsb(sy); > + asm volatile("yield" ::: "memory"); > + } > And otherwise...........? I guess it would be NOP, so do nothing - is this expected behavior? -Josh