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 X-Spam-Level: X-Spam-Status: No, score=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0A99EC4742C for ; Wed, 11 Nov 2020 17:52:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 919682072C for ; Wed, 11 Nov 2020 17:52:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727001AbgKKRwy (ORCPT ); Wed, 11 Nov 2020 12:52:54 -0500 Received: from foss.arm.com ([217.140.110.172]:59128 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725860AbgKKRww (ORCPT ); Wed, 11 Nov 2020 12:52:52 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id F37CE139F; Wed, 11 Nov 2020 09:52:51 -0800 (PST) Received: from bogus (unknown [10.57.15.107]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B852D3F718; Wed, 11 Nov 2020 09:52:50 -0800 (PST) Date: Wed, 11 Nov 2020 17:52:43 +0000 From: Sudeep Holla To: Cristian Marussi Cc: Jim Quinlan , "maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE" , open list Subject: Re: [PATCH v1 2/2] firmware: arm_scmi: Augment SMC/HVC to allow optional interrupt Message-ID: <20201111175243.immpc2wa6hap3nhl@bogus> References: <20201110183827.19731-1-james.quinlan@broadcom.com> <20201110183827.19731-2-james.quinlan@broadcom.com> <20201111104157.wpll6en4qvlhb2ws@bogus> <20201111174546.GI42652@e120937-lin> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201111174546.GI42652@e120937-lin> User-Agent: NeoMutt/20171215 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 11, 2020 at 05:45:46PM +0000, Cristian Marussi wrote: > On Wed, Nov 11, 2020 at 11:45:24AM -0500, Jim Quinlan wrote: > > On Wed, Nov 11, 2020 at 5:42 AM Sudeep Holla wrote: > > > > > > On Tue, Nov 10, 2020 at 01:38:19PM -0500, Jim Quinlan wrote: > > > > The SMC/HVC SCMI transport is modified to allow the completion of an SCMI > > > > message to be indicated by an interrupt rather than the return of the smc > > > > call. This accommodates the existing behavior of the BrcmSTB SCMI > > > > "platform" whose SW is already out in the field and cannot be changed. > > > > > > > > Signed-off-by: Jim Quinlan > > > > --- > > > > drivers/firmware/arm_scmi/smc.c | 31 +++++++++++++++++++++++++++++++ > > > > 1 file changed, 31 insertions(+) > > > > > > > > diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c > > > > index 82a82a5dc86a..3bf935dbd00e 100644 > > > > --- a/drivers/firmware/arm_scmi/smc.c > > > > +++ b/drivers/firmware/arm_scmi/smc.c > > > > @@ -9,9 +9,11 @@ > > > > #include > > > > #include > > > > #include > > > > +#include > > > > #include > > > > #include > > > > #include > > > > +#include > > > > #include > > > > > > > > #include "common.h" > > > > @@ -23,6 +25,8 @@ > > > > * @shmem: Transmit/Receive shared memory area > > > > * @shmem_lock: Lock to protect access to Tx/Rx shared memory area > > > > * @func_id: smc/hvc call function id > > > > + * @irq: Optional; employed when platforms indicates msg completion by intr. > > > > + * @tx_complete: Optional, employed only when irq is valid. > > > > */ > > > > > > > > struct scmi_smc { > > > > @@ -30,8 +34,19 @@ struct scmi_smc { > > > > struct scmi_shared_mem __iomem *shmem; > > > > struct mutex shmem_lock; > > > > u32 func_id; > > > > + int irq; > > > > + struct completion tx_complete; > > > > }; > > > > > > > > +static irqreturn_t smc_msg_done_isr(int irq, void *data) > > > > +{ > > > > + struct scmi_smc *scmi_info = data; > > > > + > > > > + complete(&scmi_info->tx_complete); > > > > + > > > > + return IRQ_HANDLED; > > > > +} > > > > + > > > > static bool smc_chan_available(struct device *dev, int idx) > > > > { > > > > struct device_node *np = of_parse_phandle(dev->of_node, "shmem", 0); > > > > @@ -79,6 +94,20 @@ static int smc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, > > > > if (ret < 0) > > > > return ret; > > > > > > > > + /* Optional feature -- signal message completion using an interrupt */ > > > > + ret = of_irq_get_byname(cdev->of_node, "msg-serviced"); > > > > > > So, looks like it is mandatory if "interrupts" is used. Please update the > > > binding or if that is not the practice followed elsewhere, drop search by > > > name. > > > > Well, I can certainly change the comment. I do not want it to be > > "mandatory" if just interrupts are used. > > The reason I prefer using "interrupt-names" is that this allows > > unforeseen use of future additional interrupts w/o caring about order > > in the interrupts DT node. If you are absolutely positive that there > > will never be other interrupts used in the future for the SCMI node > > then I will drop it. > > Good point, please make it required property then if "interrupts" property is present. > > What about the future possibility of adding p2a notifications handling > to SMC transport, won't that need some other IRQ (and shmem) ? > Indeed it needs. Since this Tx completion interrupt is optional and may not be present, better to fix the name so that when Rx/notification interrupt is added in future, we can identify them easily. -- Regards, Sudeep