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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 3FA57C4320A for ; Wed, 28 Jul 2021 14:35:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1629A60F91 for ; Wed, 28 Jul 2021 14:35:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235479AbhG1Ofq (ORCPT ); Wed, 28 Jul 2021 10:35:46 -0400 Received: from foss.arm.com ([217.140.110.172]:57866 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235521AbhG1Ofl (ORCPT ); Wed, 28 Jul 2021 10:35:41 -0400 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 463071042; Wed, 28 Jul 2021 07:35:39 -0700 (PDT) Received: from bogus (unknown [10.57.37.191]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 31B7E3F70D; Wed, 28 Jul 2021 07:35:35 -0700 (PDT) Date: Wed, 28 Jul 2021 15:34:18 +0100 From: Sudeep Holla To: Cristian Marussi Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, virtualization@lists.linux-foundation.org, virtio-dev@lists.oasis-open.org, james.quinlan@broadcom.com, Jonathan.Cameron@Huawei.com, f.fainelli@gmail.com, etienne.carriere@linaro.org, vincent.guittot@linaro.org, souvik.chakravarty@arm.com, igor.skalkin@opensynergy.com, peter.hilber@opensynergy.com, alex.bennee@linaro.org, jean-philippe@linaro.org, mikhail.golubev@opensynergy.com, anton.yakovlev@opensynergy.com, Vasyl.Vavrychuk@opensynergy.com, Sudeep Holla , Andriy.Tryshnivskyy@opensynergy.com Subject: Re: [PATCH v6 10/17] firmware: arm_scmi: Make polling mode optional Message-ID: <20210728143418.5lton6l7t2oa6rtz@bogus> References: <20210712141833.6628-1-cristian.marussi@arm.com> <20210712141833.6628-11-cristian.marussi@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210712141833.6628-11-cristian.marussi@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 12, 2021 at 03:18:26PM +0100, Cristian Marussi wrote: > Add a check for the presence of .poll_done transport operation so that > transports that do not need to support polling mode have no need to provide > a dummy .poll_done callback either and polling mode can be disabled in the > SCMI core for that tranport. > > Signed-off-by: Cristian Marussi > --- > drivers/firmware/arm_scmi/driver.c | 43 ++++++++++++++++++------------ > 1 file changed, 26 insertions(+), 17 deletions(-) > > diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c > index a952b6527b8a..4183d25c9289 100644 > --- a/drivers/firmware/arm_scmi/driver.c > +++ b/drivers/firmware/arm_scmi/driver.c > @@ -777,25 +777,34 @@ static int do_xfer(const struct scmi_protocol_handle *ph, > } > > if (xfer->hdr.poll_completion) { > - ktime_t stop = ktime_add_ns(ktime_get(), SCMI_MAX_POLL_TO_NS); > - > - spin_until_cond(scmi_xfer_done_no_timeout(cinfo, xfer, stop)); > - > - if (ktime_before(ktime_get(), stop)) { > - unsigned long flags; > - > - /* > - * Do not fetch_response if an out-of-order delayed > - * response is being processed. > - */ > - spin_lock_irqsave(&xfer->lock, flags); > - if (xfer->state == SCMI_XFER_SENT_OK) { > - info->desc->ops->fetch_response(cinfo, xfer); > - xfer->state = SCMI_XFER_RESP_OK; > + if (info->desc->ops->poll_done) { > + ktime_t stop = ktime_add_ns(ktime_get(), > + SCMI_MAX_POLL_TO_NS); > + > + spin_until_cond(scmi_xfer_done_no_timeout(cinfo, xfer, > + stop)); > + > + if (ktime_before(ktime_get(), stop)) { > + unsigned long flags; > + > + /* > + * Do not fetch_response if an out-of-order delayed > + * response is being processed. > + */ > + spin_lock_irqsave(&xfer->lock, flags); > + if (xfer->state == SCMI_XFER_SENT_OK) { > + info->desc->ops->fetch_response(cinfo, > + xfer); > + xfer->state = SCMI_XFER_RESP_OK; > + } > + spin_unlock_irqrestore(&xfer->lock, flags); > + } else { > + ret = -ETIMEDOUT; > } > - spin_unlock_irqrestore(&xfer->lock, flags); > } else { > - ret = -ETIMEDOUT; > + dev_warn_once(dev, > + "Polling mode is not supported by transport.\n"); > + ret = EINVAL; Can't we just return this error as early as possible if the user isn't expected to use polling with this transport ? That would simplify the patch (as most of it is due to indentation which can go away) as you need not check it later ? -- Regards, Sudeep