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: 4642091 Return-Path: X-Original-To: patchwork-linux-arm@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 9451FC0338 for ; Tue, 29 Jul 2014 19:03:10 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C777E20149 for ; Tue, 29 Jul 2014 19:03:09 +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 0257920123 for ; Tue, 29 Jul 2014 19:03:09 +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 1XCCeQ-00052b-JO; Tue, 29 Jul 2014 19:01:30 +0000 Received: from galois.linutronix.de ([2001:470:1f0b:db:abcd:42:0:1]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XCCdb-0004Np-Bl for linux-arm-kernel@lists.infradead.org; Tue, 29 Jul 2014 19:00:42 +0000 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 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140729_120039_603395_7CF1147E X-CRM114-Status: GOOD ( 12.59 ) X-Spam-Score: -0.7 (/) Cc: tony@atomide.com, Vinod Koul , Sebastian Andrzej Siewior , linux-kernel@vger.kernel.org, balbi@ti.com, Joel Fernandes , dmaengine@vger.kernel.org, Dan Williams , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org 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: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,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);