From mboxrd@z Thu Jan 1 00:00:00 1970 From: tixy@linaro.org (Jon Medhurst (Tixy)) Date: Thu, 13 Nov 2014 16:27:27 +0000 Subject: [PATCH] dmaengine: pl330: Fix linker error "undefined reference to `__aeabi_uldivmod'" Message-ID: <1415896047.1787.4.camel@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.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