Re: [PATCH v5 1/6] dma-buf: Add dma_buf_{begin,end}_access()

kernel test robot
2024-01-20T20:20:57Z

Hi Paul,

kernel test robot noticed the following build warnings:

[auto build test WARNING on usb/usb-testing]
[also build test WARNING on usb/usb-next usb/usb-linus drm-misc/drm-misc-next lwn/docs-next linus/master v6.7 next-20240119]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Paul-Cercueil/dma-buf-Add-dma_buf_-begin-end-_access/20240119-221604
base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
patch link: https://lore.kernel.org/r/20240119141402.44262-2-paul%40crapouillou.net
patch subject: [PATCH v5 1/6] dma-buf: Add dma_buf_{begin,end}_access()
config: arm-randconfig-001-20240120 (https://download.01.org/0day-ci/archive/20240121/202401210406.YYgVcAC1-lkp@intel.com/config)
compiler: clang version 18.0.0git (https://github.com/llvm/llvm-project d92ce344bf641e6bb025b41b3f1a77dd25e2b3e9)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240121/202401210406.YYgVcAC1-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202401210406.YYgVcAC1-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/dma-buf/dma-buf.c:1608: warning: Cannot understand * @dma_buf_begin_access - Call before any hardware access from/to the DMABUF
on line 1608 - I thought it was a doc line
>> drivers/dma-buf/dma-buf.c:1640: warning: Cannot understand * @dma_buf_end_access - Call after any hardware access from/to the DMABUF
on line 1640 - I thought it was a doc line

vim +1608 drivers/dma-buf/dma-buf.c

1606
1607 /**
> 1608 * @dma_buf_begin_access - Call before any hardware access from/to the DMABUF
1609 * @attach: [in] attachment used for hardware access
1610 * @sg_table: [in] scatterlist used for the DMA transfer
1611 * @direction: [in] direction of DMA transfer
1612 */
1613 int dma_buf_begin_access(struct dma_buf_attachment *attach,
1614 struct sg_table *sgt, enum dma_data_direction dir)
1615 {
1616 struct dma_buf *dmabuf;
1617 bool cookie;
1618 int ret;
1619
1620 if (WARN_ON(!attach))
1621 return -EINVAL;
1622
1623 dmabuf = attach->dmabuf;
1624
1625 if (!dmabuf->ops->begin_access)
1626 return 0;
1627
1628 cookie = dma_fence_begin_signalling();
1629 ret = dmabuf->ops->begin_access(attach, sgt, dir);
1630 dma_fence_end_signalling(cookie);
1631
1632 if (WARN_ON_ONCE(ret))
1633 return ret;
1634
1635 return 0;
1636 }
1637 EXPORT_SYMBOL_NS_GPL(dma_buf_begin_access, DMA_BUF);
1638
1639 /**
> 1640 * @dma_buf_end_access - Call after any hardware access from/to the DMABUF
1641 * @attach: [in] attachment used for hardware access
1642 * @sg_table: [in] scatterlist used for the DMA transfer
1643 * @direction: [in] direction of DMA transfer
1644 */
1645 int dma_buf_end_access(struct dma_buf_attachment *attach,
1646 struct sg_table *sgt, enum dma_data_direction dir)
1647 {
1648 struct dma_buf *dmabuf;
1649 bool cookie;
1650 int ret;
1651
1652 if (WARN_ON(!attach))
1653 return -EINVAL;
1654
1655 dmabuf = attach->dmabuf;
1656
1657 if (!dmabuf->ops->end_access)
1658 return 0;
1659
1660 cookie = dma_fence_begin_signalling();
1661 ret = dmabuf->ops->end_access(attach, sgt, dir);
1662 dma_fence_end_signalling(cookie);
1663
1664 if (WARN_ON_ONCE(ret))
1665 return ret;
1666
1667 return 0;
1668 }
1669 EXPORT_SYMBOL_NS_GPL(dma_buf_end_access, DMA_BUF);
1670

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