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 82FFDC47083 for ; Wed, 2 Jun 2021 16:09:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6BFAA61928 for ; Wed, 2 Jun 2021 16:09:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229586AbhFBQKo (ORCPT ); Wed, 2 Jun 2021 12:10:44 -0400 Received: from foss.arm.com ([217.140.110.172]:48786 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229607AbhFBQKn (ORCPT ); Wed, 2 Jun 2021 12:10:43 -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 DC5F012FC; Wed, 2 Jun 2021 09:08:59 -0700 (PDT) Received: from bogus (unknown [10.57.72.241]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7E5D13F73D; Wed, 2 Jun 2021 09:08:57 -0700 (PDT) Date: Wed, 2 Jun 2021 17:08:53 +0100 From: Sudeep Holla To: Cristian Marussi Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, james.quinlan@broadcom.com, Jonathan.Cameron@Huawei.com, f.fainelli@gmail.com, etienne.carriere@linaro.org, Sudeep Holla , vincent.guittot@linaro.org, souvik.chakravarty@arm.com Subject: Re: [PATCH v2 1/5] firmware: arm_scmi: reset_rx_to_maxsz during async commands Message-ID: <20210602160853.mui3xdr7v4cmmwn2@bogus> References: <20210601102421.26581-1-cristian.marussi@arm.com> <20210601102421.26581-2-cristian.marussi@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210601102421.26581-2-cristian.marussi@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 01, 2021 at 11:24:17AM +0100, Cristian Marussi wrote: > During an async commands execution the rx buffer len is at first set to > max_msg_sz when the synchronous part of the command is first sent; once > the synchronous part completes the transport layer waits for the delayed > response which will be processed using the same xfer descriptor initially > allocated, but synchronous response received at the end of the xfer will > have shrunk the rx buffer len to the effective payload response length. > > Raise the rx buffer length again to max_msg_sz while waiting for the > delayed response, while adding an informational error message. > > Fixes: 58ecdf03dbb9 ("firmware: arm_scmi: Add support for asynchronous commands and delayed response") > Signed-off-by: Cristian Marussi > --- > drivers/firmware/arm_scmi/driver.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c > index 66eb3f0e5daf..75141b90ae53 100644 > --- a/drivers/firmware/arm_scmi/driver.c > +++ b/drivers/firmware/arm_scmi/driver.c > @@ -513,8 +513,16 @@ static int do_xfer_with_response(const struct scmi_protocol_handle *ph, > xfer->async_done = &async_response; > > ret = do_xfer(ph, xfer); > - if (!ret && !wait_for_completion_timeout(xfer->async_done, timeout)) > - ret = -ETIMEDOUT; > + if (!ret) { > + /* rx.len would have been shrunk in the sync do_xfer above */ > + reset_rx_to_maxsz(ph, xfer); Won't this race with delayed response notification ? I think so, let me know if not and how. Can't we have this before we fetch the response into xfer ? -- Regards, Sudeep