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=-11.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 A6E7CC56201 for ; Thu, 12 Nov 2020 16:16:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2150D22227 for ; Thu, 12 Nov 2020 16:16:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=metafoo.de header.i=@metafoo.de header.b="DSqkqFqU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728492AbgKLQQC (ORCPT ); Thu, 12 Nov 2020 11:16:02 -0500 Received: from www381.your-server.de ([78.46.137.84]:57360 "EHLO www381.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728414AbgKLQQC (ORCPT ); Thu, 12 Nov 2020 11:16:02 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=metafoo.de; s=default2002; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID; bh=d8x8Foilk6qHJkAC/FTtooebxxTve4qGtSTr90knXjE=; b=DSqkqFqU8Vy2bjGnSbqwniS6Me eUBUCsv+wmZX5U6u5yXq1vjIvOjNPXrP1K6vg6YH3ZJuV4yc92RiEgFJTVIAXD7gNS4zHflRylo64 w1t7LmUL/u7ROeFnQI6vak8PJ0z5FJ+7k7yI5qF/Jzm9kx/vI0NgpEbJToUMjocwB92conEglJpt3 XmNwbJlMb9vmUHpm1lpx+YK+tK5HLC9pyhOduQaXPhaSP8e6prnMSzltBdWvE1GNBGqHHqtsSvVMN oCig0DXHhJKPzPjznXze5RmHSVTQ4FH5GzN71BdPUiHl6fLj5vV0GF0cJU8oTNcqpyeGYseIBMjGM vFg03Qhw==; Received: from sslproxy03.your-server.de ([88.198.220.132]) by www381.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92.3) (envelope-from ) id 1kdFGP-0007NL-Bo; Thu, 12 Nov 2020 17:15:57 +0100 Received: from [62.216.202.98] (helo=[192.168.178.20]) by sslproxy03.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kdFGP-0003lA-7T; Thu, 12 Nov 2020 17:15:57 +0100 Subject: Re: [RFC PATCH 1/1] iio: buffer: Sanity check buffer callback To: =?UTF-8?Q?Nuno_S=c3=a1?= , linux-iio@vger.kernel.org Cc: Jonathan Cameron , Peter Meerwald-Stadler References: <20201112151334.32167-1-nuno.sa@analog.com> <20201112151334.32167-2-nuno.sa@analog.com> From: Lars-Peter Clausen Message-ID: Date: Thu, 12 Nov 2020 17:15:57 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: <20201112151334.32167-2-nuno.sa@analog.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Authenticated-Sender: lars@metafoo.de X-Virus-Scanned: Clear (ClamAV 0.102.4/25986/Thu Nov 12 14:18:25 2020) Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On 11/12/20 4:13 PM, Nuno Sá wrote: > Make sure that a callback is actually present before trying to call > it... > > Signed-off-by: Nuno Sá > --- > drivers/iio/buffer/industrialio-buffer-cb.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/iio/buffer/industrialio-buffer-cb.c b/drivers/iio/buffer/industrialio-buffer-cb.c > index 47c96f7f4976..b4385f59399d 100644 > --- a/drivers/iio/buffer/industrialio-buffer-cb.c > +++ b/drivers/iio/buffer/industrialio-buffer-cb.c > @@ -27,6 +27,10 @@ static struct iio_cb_buffer *buffer_to_cb_buffer(struct iio_buffer *buffer) > static int iio_buffer_cb_store_to(struct iio_buffer *buffer, const void *data) > { > struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer); > + > + if (!cb_buff->cb) > + return 0; > + I think it makes more sense to check this once when the buffer is registered instead of every time we want to call the function.