From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Tue, 22 Apr 2025 10:38:20 +0200 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1u7992-003yTu-1O for lore@lore.pengutronix.de; Tue, 22 Apr 2025 10:38:20 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1u798z-0001I5-Tl for lore@pengutronix.de; Tue, 22 Apr 2025 10:38:20 +0200 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:Content-Transfer-Encoding: MIME-Version:Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=iqaPbcHzO2yVjryuXWXMXvHFtQlbw2beEw3AE1CI0UQ=; b=bC6aWr7K8Iac+u4KQUUVvGoFly 6WZqTyl4JGrLPPHwjnH62Q4lxKJRSqRglkHvvBX2y+nxxXsWtJmtTaf7CHaheLyrBeD2Sw5gRx+Le tSxNkxWmzblHfLCv4pxFSgqp1kmuU4z6BIAsw+uzywW6jlCDfGCEkZOLOwJBbrny80Sku1MGHID5U ckmNNgRBRGjrJ9uEC6d3ggKeVdG5hjBcmN+fj2NiNiQieI9AftEOmedrw5Gr01ZGofW2RN5RaGyTe V/0f92s84gQuiTskZiAXH/vFoV7Q05ed6fXFFYfY+aBteIVNWFl9gp7BwxPTGM2CbXUt0KDO07AAZ bajaTV0g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1u798X-00000006M1k-3rAJ; Tue, 22 Apr 2025 08:37:49 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1u78Ss-00000006Byf-293v for barebox@lists.infradead.org; Tue, 22 Apr 2025 07:54:47 +0000 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1u78Sr-0000Qb-39; Tue, 22 Apr 2025 09:54:45 +0200 Received: from dude05.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::54]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1u78Sq-001Vv1-2w; Tue, 22 Apr 2025 09:54:44 +0200 Received: from localhost ([::1] helo=dude05.red.stw.pengutronix.de) by dude05.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1u78Sq-000uqL-2e; Tue, 22 Apr 2025 09:54:44 +0200 From: Ahmad Fatoum To: barebox@lists.infradead.org Cc: Ahmad Fatoum Date: Tue, 22 Apr 2025 09:54:44 +0200 Message-Id: <20250422075444.218493-1-a.fatoum@pengutronix.de> X-Mailer: git-send-email 2.39.5 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250422_005446_545980_570FC30F X-CRM114-Status: UNSURE ( 8.32 ) X-CRM114-Notice: Please train this message. X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-5.4 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: [PATCH] stddev: make reads from /dev/null return 0 bytes X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) Currently, /dev/null discards all writes, but returns -ENOSYS on read. Implement read to return 0 always, so it returns EOF immediately. Signed-off-by: Ahmad Fatoum --- commands/stddev.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/commands/stddev.c b/commands/stddev.c index e9b7dcc0d2f3..16cf4e30802d 100644 --- a/commands/stddev.c +++ b/commands/stddev.c @@ -64,8 +64,14 @@ static ssize_t null_write(struct cdev *cdev, const void *buf, size_t count, loff return count; } +static ssize_t null_read(struct cdev *cdev, void *buf, size_t count, loff_t offset, ulong flags) +{ + return 0; +} + static struct cdev_operations nullops = { .write = null_write, + .read = null_read, }; static int null_init(void) -- 2.39.5