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=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 2BE7ECA9EA0 for ; Fri, 25 Oct 2019 18:11:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 01F88222C1 for ; Fri, 25 Oct 2019 18:11:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731671AbfJYSGz (ORCPT ); Fri, 25 Oct 2019 14:06:55 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:46810 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731448AbfJYSFo (ORCPT ); Fri, 25 Oct 2019 14:05:44 -0400 Received: from [167.98.27.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iO3xv-0008OD-KC; Fri, 25 Oct 2019 19:05:35 +0100 Received: from ben by deadeye with local (Exim 4.92.2) (envelope-from ) id 1iO3xu-0001hd-Qz; Fri, 25 Oct 2019 19:05:34 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Russell King" Date: Fri, 25 Oct 2019 19:03:03 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 02/47] ARM: riscpc: fix DMA In-Reply-To: X-SA-Exim-Connect-IP: 167.98.27.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 3.16.76-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Russell King commit ffd9a1ba9fdb7f2bd1d1ad9b9243d34e96756ba2 upstream. DMA got broken a while back in two different ways: 1) a change in the behaviour of disable_irq() to wait for the interrupt to finish executing causes us to deadlock at the end of DMA. 2) a change to avoid modifying the scatterlist left the first transfer uninitialised. DMA is only used with expansion cards, so has gone unnoticed. Fixes: fa4e99899932 ("[ARM] dma: RiscPC: don't modify DMA SG entries") Signed-off-by: Russell King Signed-off-by: Ben Hutchings --- arch/arm/mach-rpc/dma.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/arch/arm/mach-rpc/dma.c +++ b/arch/arm/mach-rpc/dma.c @@ -131,7 +131,7 @@ static irqreturn_t iomd_dma_handle(int i } while (1); idma->state = ~DMA_ST_AB; - disable_irq(irq); + disable_irq_nosync(irq); return IRQ_HANDLED; } @@ -174,6 +174,9 @@ static void iomd_enable_dma(unsigned int DMA_FROM_DEVICE : DMA_TO_DEVICE); } + idma->dma_addr = idma->dma.sg->dma_address; + idma->dma_len = idma->dma.sg->length; + iomd_writeb(DMA_CR_C, dma_base + CR); idma->state = DMA_ST_AB; }