Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754019AbaKMQ1c (ORCPT ); Thu, 13 Nov 2014 11:27:32 -0500 Received: from smarthost01d.mail.zen.net.uk ([212.23.1.7]:55721 "EHLO smarthost01d.mail.zen.net.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753928AbaKMQ1b (ORCPT ); Thu, 13 Nov 2014 11:27:31 -0500 X-Greylist: delayed 22075 seconds by postgrey-1.27 at vger.kernel.org; Thu, 13 Nov 2014 11:27:31 EST Message-ID: <1415896047.1787.4.camel@linaro.org> Subject: [PATCH] dmaengine: pl330: Fix linker error "undefined reference to `__aeabi_uldivmod'" From: "Jon Medhurst (Tixy)" To: Vinod Koul , dmaengine@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Date: Thu, 13 Nov 2014 16:27:27 +0000 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.7-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Originating-smarthost01d-IP: [82.69.122.217] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 32-bit ARM kernels may have a 64-bit dma_addr_t but have no implementation of the compiler helper for 64-bit unsigned division, therefore the use of the modulo operator in pl330_prep_dma_memcpy causes the link error "undefined reference to `__aeabi_uldivmod'" As the burst value is always a power of two we can fix the problem, and make the code more efficient, by replacing "% burst" with "& (burst-1)". Reported-by: kbuild test robot Signed-off-by: Jon Medhurst --- Vinod. I haven't added a 'Fixes:' line because I was unsure if the patch in linux-next is part of a stable branch or if the SHA1 might change before hitting mainline. If it stable then the line should be... Fixes: 63369d0a96dc ("dmaengine: pl330: Align DMA memcpy operations to MFIFO width") drivers/dma/pl330.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index 38c9617..52c4c62 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2464,11 +2464,8 @@ pl330_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dst, * parameters because our DMA programming algorithm doesn't cope with * transfers which straddle an entry in the DMA device's MFIFO. */ - while (burst > 1) { - if (!((src | dst | len) % burst)) - break; + while ((src | dst | len) & (burst - 1)) burst /= 2; - } desc->rqcfg.brst_size = 0; while (burst != (1 << desc->rqcfg.brst_size)) -- 2.1.1 -- 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/