From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?q?Niklas=20S=C3=B6derlund?= Subject: [PATCH 0/2] Fix incorrect warning from dma-debug Date: Sun, 8 May 2016 12:59:54 +0200 Message-ID: <1462705196-10857-1-git-send-email-niklas.soderlund+renesas@ragnatech.se> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Sender: linux-renesas-soc-owner@vger.kernel.org To: linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, dmaengine@vger.kernel.org Cc: will.deacon@arm.com, robin.murphy@arm.com, joro@8bytes.org, linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, =?UTF-8?q?Niklas=20S=C3=B6derlund?= List-Id: iommu@lists.linux-foundation.org Hi, While using CONFIG_DMA_API_DEBUG i came across this warning which I think is a false positive. As shown dma_sync_single_for_device() are called from the dma_map_single() call path. This triggers the warning since the dma-debug code have not yet been made aware of the mapping. I try to solve this by introducing __dma_sync_single_for_device() which do not call into the dma-debug code. I'm no expert and this might be a bad way of solving the problem but it allowed me to keep working. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1 at lib/dma-debug.c:1209 check_sync+0x154/0x5e4 ipmmu-vmsa e6740000.mmu: DMA-API: device driver tries to sync DMA memor= y it has not allocated [device address=3D0x000000006e89b008] [size=3D8 = bytes] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.6.0-rc5-00012-g52e78c1-dirt= y #1 Hardware name: Generic R8A7791 (Flattened Device Tree) Backtrace: [] (dump_backtrace) from [] (show_stack+0x18/0x1c) r7:c03ebad0 r6:00000009 r5:60000093 r4:00000000 [] (show_stack) from [] (dump_stack+0x84/0xa4) [] (dump_stack) from [] (__warn+0xd0/0x100) r5:00000000 r4:ef05dac8 [] (__warn) from [] (warn_slowpath_fmt+0x40/0x48) r9:00010000 r8:00000000 r7:c0c69c40 r6:c0c02754 r5:ef05db78 r4:ef22281= 0 [] (warn_slowpath_fmt) from [] (check_sync+0x154/0x= 5e4) r3:c0945b6f r2:c0936e85 [] (check_sync) from [] (debug_dma_sync_single_for_= device+0x64/0x70) r10:00000009 r9:0000000c r8:ee89b008 r7:00000000 r6:6e89b008 r5:000000= 00 r4:6e89b008 [] (debug_dma_sync_single_for_device) from [] (__ar= m_lpae_set_pte.part.0+0x80/0x8c) r5:00000001 r4:ef222810 [] (__arm_lpae_set_pte.part.0) from [] (__arm_lpae_= map+0x298/0x2f0) r7:00000008 r6:ef25e000 r4:ee898500 [] (__arm_lpae_map) from [] (arm_lpae_map+0xcc/0xe4= ) r10:c0465f40 r9:00001000 r8:40000000 r7:00000000 r6:6f25c000 r5:000000= 00 r4:000008c0 [] (arm_lpae_map) from [] (ipmmu_map+0x38/0x40) r7:40000000 r6:00000000 r5:00001000 r4:c0465a4c [] (ipmmu_map) from [] (iommu_map+0xf8/0x15c) r4:ee895608 [] (iommu_map) from [] (arm_coherent_iommu_map_page= +0x1d4/0x2d4) r10:ef386940 r9:00001000 r8:00000000 r7:00000000 r6:40000000 r5:000000= 00 r4:00000000 [] (arm_coherent_iommu_map_page) from [] (arm_iommu= _map_page+0x6c/0x74) r10:c0c61f44 r9:ef19d210 r8:00000001 r7:00001000 r6:00000000 r5:ec5ddb= 80 r4:00000000 [] (arm_iommu_map_page) from [] (sh_msiof_spi_probe= +0x430/0x7b0) r9:00000000 r8:c0213624 r7:ef19d210 r6:ef242800 r5:ef1b4010 r4:ef242af= 0 [] (sh_msiof_spi_probe) from [] (platform_drv_probe= +0x58/0xa8) r10:00000000 r9:00000000 r8:c0c1f8d4 r7:c0c7e910 r6:c0c1f8d4 r5:ef1b40= 10 r4:c04f7934 [] (platform_drv_probe) from [] (driver_probe_devic= e+0x13c/0x2a4) r7:c0c7e910 r6:00000000 r5:c0c7e900 r4:ef1b4010 [] (driver_probe_device) from [] (__driver_attach+0= x88/0xac) r9:c0c34000 r8:c0a3c010 r7:c0c1cf08 r6:c0c1f8d4 r5:ef1b4044 r4:ef1b401= 0 [] (__driver_attach) from [] (bus_for_each_dev+0x74= /0x98) r7:c0c1cf08 r6:c049e8f0 r5:c0c1f8d4 r4:00000000 [] (bus_for_each_dev) from [] (driver_attach+0x20/0= x28) r6:ef1cc200 r5:00000000 r4:c0c1f8d4 [] (driver_attach) from [] (bus_add_driver+0xd4/0x1= e4) [] (bus_add_driver) from [] (driver_register+0xa4/0= xe8) r7:c0a3c010 r6:00000000 r5:c0a1e400 r4:c0c1f8d4 [] (driver_register) from [] (__platform_driver_reg= ister+0x38/0x4c) r5:c0a1e400 r4:ee958fc0 [] (__platform_driver_register) from [] (sh_msiof_s= pi_drv_init+0x18/0x20) [] (sh_msiof_spi_drv_init) from [] (do_one_initcall= +0x10c/0x1c0) [] (do_one_initcall) from [] (kernel_init_freeable+= 0x128/0x1f4) r9:c0c34000 r8:c0c34000 r7:c0a47e60 r6:c0a3c83c r5:000000bd r4:0000000= 6 [] (kernel_init_freeable) from [] (kernel_init+0x10= /0x118) r9:00000000[ 1.879529] ata1: link resume succeeded after 1 retries r8:00000000 r7:00000000 r6:00000000 r5:c071066c r4:00000000 [] (kernel_init) from [] (ret_from_fork+0x14/0x2c) r5:c071066c r4:00000000 ---[ end trace 6eb9a3df3009d491 ]--- Niklas S=C3=B6derlund (2): dma-mapping: add __dma_sync_single_for_device() iommu/io-pgtable-arm: use __dma_sync_single_for_device() drivers/iommu/io-pgtable-arm.c | 2 +- include/linux/dma-mapping.h | 9 ++++++++- 2 files changed, 9 insertions(+), 2 deletions(-) -- 2.8.2