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@xxxxxxxxx/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@xxxxxxxxx/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@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202401210406.YYgVcAC1-lkp@xxxxxxxxx/ 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 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki