From patchwork Tue Jul 29 18:58:58 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 4641911 Return-Path: X-Original-To: patchwork-dmaengine@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id C2D7DC0338 for ; Tue, 29 Jul 2014 19:00:47 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id EE17D20145 for ; Tue, 29 Jul 2014 19:00:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2707E2011E for ; Tue, 29 Jul 2014 19:00:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752198AbaG2TAZ (ORCPT ); Tue, 29 Jul 2014 15:00:25 -0400 Received: from www.linutronix.de ([62.245.132.108]:50386 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751311AbaG2TAX (ORCPT ); Tue, 29 Jul 2014 15:00:23 -0400 Received: from localhost ([127.0.0.1] helo=bazinga.breakpoint.cc) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1XCCdD-0001yI-BH; Tue, 29 Jul 2014 21:00:15 +0200 From: Sebastian Andrzej Siewior To: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, tony@atomide.com, balbi@ti.com, Sebastian Andrzej Siewior , Joel Fernandes , Vinod Koul , Dan Williams , dmaengine@vger.kernel.org Subject: [PATCH 1/7] dmaengine: edma: fix two faults which happen with the 8250_dma user Date: Tue, 29 Jul 2014 20:58:58 +0200 Message-Id: <1406660344-25307-2-git-send-email-bigeasy@linutronix.de> X-Mailer: git-send-email 2.0.1 In-Reply-To: <1406660344-25307-1-git-send-email-bigeasy@linutronix.de> References: <1406660344-25307-1-git-send-email-bigeasy@linutronix.de> X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1, SHORTCIRCUIT=-0.0001 Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Spam-Status: No, score=-7.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, 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 rx path of the 8250_dma user in the RX-timeout case: - it starts the RX transfer - if the rx-timeout interrupt occures, it dmaengine_pause() the transfer - step two is dmaengine_terminate_all() on this channel. - based on dmaengine_tx_status() it learns the number of transfered bytes. - the rx interrupt occures, it does not start the RX-transfer because according to dmaengine_tx_status() the status of the current transfer is still DMA_IN_PROGRESS because the earlier dmaengine_terminate_all() did not reset this. - on rx-timeout it invokes dmaengine_pause() again. This time, it segfaults because the channel has no descriptor yet. To make the upper case work better, this patch adds dma_cookie_complete() to complete the cookie. Also it adds is an additional check for echan->edesc in case the channel has no descriptor assigned. Cc: Joel Fernandes Cc: Vinod Koul Cc: Dan Williams Cc: dmaengine@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior --- drivers/dma/edma.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c index d08c4de..ff05dd4 100644 --- a/drivers/dma/edma.c +++ b/drivers/dma/edma.c @@ -256,6 +256,7 @@ static int edma_terminate_all(struct edma_chan *echan) * echan->edesc is NULL and exit.) */ if (echan->edesc) { + dma_cookie_complete(&echan->edesc->vdesc.tx); echan->edesc = NULL; edma_stop(echan->ch_num); } @@ -282,7 +283,7 @@ static int edma_slave_config(struct edma_chan *echan, static int edma_dma_pause(struct edma_chan *echan) { /* Pause/Resume only allowed with cyclic mode */ - if (!echan->edesc->cyclic) + if (!echan->edesc || !echan->edesc->cyclic) return -EINVAL; edma_pause(echan->ch_num);