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# bad: [bfeffd155283772bbe78c6a05dec7c0128ee500c] Linux 5.0-rc1
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# good: [8fe28cb58bcb235034b64cbbb7550a8a43fd88be] Linux 4.20
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# good: [e0c38a4d1f196a4b17d2eba36afff8f656a4f1de] Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
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# bad: [02061181d3a9ccfe15ef6bc15fa56283acc47620] Merge tag 'staging-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
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# bad: [75f95da078b2891cd186f074ffc15a8e7c3f082d] Merge tag 'libnvdimm-for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
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# good: [0e9da3fbf7d81f0f913b491c8de1ba7883d4f217] Merge tag 'for-4.21/block-20181221' of git://git.kernel.dk/linux-block
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# good: [5534d444802d623047fa4e0f5874057628b38246] drm/fb-helper: Blacklist writeback when adding connectors to fbdev
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# good: [da7903092b880b25971ca9103cb0b934a44ace2b] scsi: isci: request: mark expected switch fall-through
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# good: [6feb64ffda7c8efc0ea25bc81866515ba80cdc04] RDMA/srpt: Remove driver version and release date
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# bad: [af7ddd8a627c62a835524b3f5b471edbbbcce025] Merge tag 'dma-mapping-4.21' of git://git.infradead.org/users/hch/dma-mapping
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# good: [ce65d36f3ea79368170ca58f2efd28cdba3d70e9] sparc: remove the sparc32_dma_ops indirection
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# bad: [664204410afb3b0f538d176ad0c2713b04abd4b9] PCI: Remove unused attr variable in pci_dma_configure
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# good: [3731c3d4774e38b9d91c01943e1e6a243c1776be] dma-mapping: always build the direct mapping code
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# good: [58dfd4ac022037c6a562e92fc6d2a778819b2162] dma-direct: improve addressability error reporting
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# bad: [190d4e5916a2d70a11009022b968fca948fb5dc7] vmd: use the proper dma_* APIs instead of direct methods calls
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# bad: [55897af63091ebc2c3f239c6a6666f748113ac50] dma-direct: merge swiotlb_dma_ops into the dma_direct code
git bisect bad 55897af63091ebc2c3f239c6a6666f748113ac50
# good: [17ac524719f3fc88c1a90528f4789e4b4f618512] dma-direct: use dma_direct_map_page to implement dma_direct_map_sg
git bisect good 17ac524719f3fc88c1a90528f4789e4b4f618512
# first bad commit: [55897af63091ebc2c3f239c6a6666f748113ac50] dma-direct: merge swiotlb_dma_ops into the dma_direct code

---------

55897af63091ebc2c3f239c6a6666f748113ac50 is the first bad commit
commit 55897af63091ebc2c3f239c6a6666f748113ac50
Author: Christoph Hellwig <hch@lst.de>
Date:   Mon Dec 3 11:43:54 2018 +0100

    dma-direct: merge swiotlb_dma_ops into the dma_direct code
    
    While the dma-direct code is (relatively) clean and simple we actually
    have to use the swiotlb ops for the mapping on many architectures due
    to devices with addressing limits.  Instead of keeping two
    implementations around this commit allows the dma-direct
    implementation to call the swiotlb bounce buffering functions and
    thus share the guts of the mapping implementation.  This also
    simplified the dma-mapping setup on a few architectures where we
    don't have to differenciate which implementation to use.
    
    Signed-off-by: Christoph Hellwig <hch@lst.de>
    Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
    Tested-by: Jesper Dangaard Brouer <brouer@redhat.com>
    Tested-by: Tony Luck <tony.luck@intel.com>

:040000 040000 e9b0807231777e3da732cb3f744a8867f3128f90 95962d177078f04ae1bd66f560c87a9eed9d0f0e M      arch
:040000 040000 e7a90740563e49061bb6baf6413e9de37a919820 b537630e5cf02def1bcfac744cd06da0f8201ff8 M      include
:040000 040000 4698daf585ffbc830cfda58e8a2e8390f66b4cf9 a942b6a22ca5f49aaef13490a03e4589766fd497 M      kernel