Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756219AbbLWLPJ (ORCPT ); Wed, 23 Dec 2015 06:15:09 -0500 Received: from us01smtprelay-2.synopsys.com ([198.182.47.9]:51165 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754840AbbLWLPG (ORCPT ); Wed, 23 Dec 2015 06:15:06 -0500 Subject: Re: ARC AXS101 problems with linux next-20151221 To: Christoph Hellwig References: <56784531.1000007@synopsys.com> CC: Carlos Palminha , "linux-snps-arc@lists.infradead.org" , "linux-mm@kvack.org" , Alexey Brodkin , lkml , "Andrew Morton" From: Vineet Gupta Message-ID: <567A8226.80308@synopsys.com> Date: Wed, 23 Dec 2015 16:44:46 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <56784531.1000007@synopsys.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.12.197.182] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3663 Lines: 106 Hi Christoph, Andrew > On Tuesday 22 December 2015 12:00 AM, Carlos Palminha wrote: > Hi guys, > > I just compiled the kernel for axs101_defconfig based on linux next tag 'next-20151221'. > I can't boot it due to the following errors causing strange stack traces after freeing unused kernel memory (check log below). > > Any clue? > Do you more info to understand the issue? ....[snip] > dw_mmc e0015000.mmc: IDMAC supports 32-bit address mode. > dw_mmc e0015000.mmc: Using internal DMA controller. > dw_mmc e0015000.mmc: Version ID is 270a > dw_mmc e0015000.mmc: DW MMC controller at irq 34,32 bit host data width,16 deep fifo > dw_mmc e0015000.mmc: 1 slots initialized > sdhci-pltfm: SDHCI platform and OF driver helper > usbcore: registered new interface driver usbhid > usbhid: USB HID core driver > NET: Registered protocol family 17 > NET: Registered protocol family 15 > ttyS3 - failed to request DMA > Freeing unused kernel memory: 928K (80002000 - 800ea000) > INFO: rcu_preempt self-detected stall on CPU > 0-...: (2100 ticks this GP) idle=011/140000000000001/0 softirq=92/92 fqs=0 > (t=2100 jiffies g=-261 c=-262 q=60) > rcu_preempt kthread starved for 2100 jiffies! g4294967035 c4294967034 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x1 > rcu_preempt S 8053879e 0 7 2 0x00000000 > > Stack Trace: > __switch_to+0x0/0x94 > __schedule+0x1c2/0x724 > schedule+0x2a/0x74 > schedule_timeout+0x126/0x198 > rcu_gp_kthread+0x5fa/0xee8 > kthread+0xe2/0xf4 > ret_from_fork+0x18/0x1c > Task dump for CPU 0: > kworker/0:1 R running 0 19 2 0x00000008 > Workqueue: events_freezable mmc_rescan [snip] It seems the dma ops rework for ARC makes kernel belly up. Patch below fixes it. -------------> >From 96b44b39dc39542894a1081e683bd21f56cae1d1 Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Wed, 23 Dec 2015 15:41:20 +0530 Subject: [PATCH] ARC: dma mapping fixes #2 Carlos Palminha reported linux-next boot broken for ARC. (1) dma_map_single() would recursively call itself | #define dma_map_single(d, a, s, r) dma_map_single_attrs(d, a, s, r, NULL) | dma_map_single_attrs | ops->map_page | arc_dma_map_page | dma_map_single (2) arc_dma_free() to iounmap if memory is coherent Signed-off-by: Vineet Gupta --- arch/arc/mm/dma.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c index 695029f41a48..01eaf88bf821 100644 --- a/arch/arc/mm/dma.c +++ b/arch/arc/mm/dma.c @@ -72,8 +72,8 @@ static void *arc_dma_alloc(struct device *dev, size_t size, static void arc_dma_free(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle, struct dma_attrs *attrs) { - if (!(is_isa_arcv2() && ioc_exists) || - dma_get_attr(DMA_ATTR_NON_CONSISTENT, attrs)) + if (!dma_get_attr(DMA_ATTR_NON_CONSISTENT, attrs) && + !(is_isa_arcv2() && ioc_exists)) iounmap((void __force __iomem *)vaddr); free_pages_exact((void *)dma_handle, size); @@ -107,7 +107,8 @@ static dma_addr_t arc_dma_map_page(struct device *dev, struct page *page, struct dma_attrs *attrs) { unsigned long paddr = page_to_phys(page) + offset; - return dma_map_single(dev, (void *)paddr, size, dir); + _dma_cache_sync(paddr, size, dir); + return (dma_addr_t)paddr; } static int arc_dma_map_sg(struct device *dev, struct scatterlist *sg, -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/