From patchwork Fri Nov 7 14:14:39 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Jackson X-Patchwork-Id: 5253441 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 6108E9F387 for ; Fri, 7 Nov 2014 14:20:53 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 9926520145 for ; Fri, 7 Nov 2014 14:20:52 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CBD482012E for ; Fri, 7 Nov 2014 14:20:51 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XmkMb-0006Vl-PV; Fri, 07 Nov 2014 14:18:09 +0000 Received: from fw-tnat.cambridge.arm.com ([217.140.96.21] helo=cam-smtp0.cambridge.arm.com) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XmkJc-0002Bn-FX for linux-arm-kernel@lists.infradead.org; Fri, 07 Nov 2014 14:15:05 +0000 Received: from [10.1.193.37] (e106787-lin.cambridge.arm.com [10.1.193.37]) by cam-smtp0.cambridge.arm.com (8.13.8/8.13.8) with ESMTP id sA7EEdDL021862; Fri, 7 Nov 2014 14:14:39 GMT Message-ID: <545CD3CF.4070901@arm.com> Date: Fri, 07 Nov 2014 14:14:39 +0000 From: Andrew Jackson User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 MIME-Version: 1.0 To: Russell King , Greg Kroah-Hartman , Jiri Slaby , linux-serial@vger.kernel.org, "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Subject: [PATCH 2/5] serial: pl011: Avoid assumptions about buffer size when refilling TX DMA X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20141107_061504_911329_F13E806D X-CRM114-Status: GOOD ( 10.24 ) X-Spam-Score: -2.9 (--) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The existing code assumed that PL011_DMA_BUFFER_SIZE == UART_XMIT_SIZE, which may not always be the case. This allows for these two being different sizes and not copying too much data. Signed-off-by: Andrew Jackson --- drivers/tty/serial/amba-pl011.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-) diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index a285196..d8d067a 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -501,7 +501,11 @@ static int pl011_dma_tx_refill(struct uart_amba_port *uap) memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], count); else { size_t first = UART_XMIT_SIZE - xmit->tail; - size_t second = xmit->head; + size_t second; + + if (first > count) + first = count; + second = count - first; memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], first); if (second)