diff options
author | Bjorn Helgaas <bhelgaas@google.com> | 2014-05-20 18:56:27 -0400 |
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committer | Bjorn Helgaas <bhelgaas@google.com> | 2014-05-26 19:28:27 -0400 |
commit | f311a724a79669ac0336932d0361325afdb54279 (patch) | |
tree | 1f86a93a676d25961f692ca5966ea1decb0a867f /Documentation/DMA-API-HOWTO.txt | |
parent | ace4b3fd67e771951d495aa1f1b1000984083362 (diff) |
DMA-API: Capitalize "CPU" consistently
Sometimes we used "cpu," other times "CPU." Use "CPU" consistently.
Suggested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'Documentation/DMA-API-HOWTO.txt')
-rw-r--r-- | Documentation/DMA-API-HOWTO.txt | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/Documentation/DMA-API-HOWTO.txt b/Documentation/DMA-API-HOWTO.txt index fd3727b94ac2..f59955303475 100644 --- a/Documentation/DMA-API-HOWTO.txt +++ b/Documentation/DMA-API-HOWTO.txt | |||
@@ -575,10 +575,10 @@ Incorrect example 2: | |||
575 | You should call dma_unmap_single() when the DMA activity is finished, e.g., | 575 | You should call dma_unmap_single() when the DMA activity is finished, e.g., |
576 | from the interrupt which told you that the DMA transfer is done. | 576 | from the interrupt which told you that the DMA transfer is done. |
577 | 577 | ||
578 | Using cpu pointers like this for single mappings has a disadvantage: | 578 | Using CPU pointers like this for single mappings has a disadvantage: |
579 | you cannot reference HIGHMEM memory in this way. Thus, there is a | 579 | you cannot reference HIGHMEM memory in this way. Thus, there is a |
580 | map/unmap interface pair akin to dma_{map,unmap}_single(). These | 580 | map/unmap interface pair akin to dma_{map,unmap}_single(). These |
581 | interfaces deal with page/offset pairs instead of cpu pointers. | 581 | interfaces deal with page/offset pairs instead of CPU pointers. |
582 | Specifically: | 582 | Specifically: |
583 | 583 | ||
584 | struct device *dev = &my_dev->dev; | 584 | struct device *dev = &my_dev->dev; |
@@ -650,7 +650,7 @@ you could render the machine unusable by consuming all bus addresses. | |||
650 | 650 | ||
651 | If you need to use the same streaming DMA region multiple times and touch | 651 | If you need to use the same streaming DMA region multiple times and touch |
652 | the data in between the DMA transfers, the buffer needs to be synced | 652 | the data in between the DMA transfers, the buffer needs to be synced |
653 | properly in order for the cpu and device to see the most up-to-date and | 653 | properly in order for the CPU and device to see the most up-to-date and |
654 | correct copy of the DMA buffer. | 654 | correct copy of the DMA buffer. |
655 | 655 | ||
656 | So, firstly, just map it with dma_map_{single,sg}(), and after each DMA | 656 | So, firstly, just map it with dma_map_{single,sg}(), and after each DMA |
@@ -665,7 +665,7 @@ or: | |||
665 | as appropriate. | 665 | as appropriate. |
666 | 666 | ||
667 | Then, if you wish to let the device get at the DMA area again, | 667 | Then, if you wish to let the device get at the DMA area again, |
668 | finish accessing the data with the cpu, and then before actually | 668 | finish accessing the data with the CPU, and then before actually |
669 | giving the buffer to the hardware call either: | 669 | giving the buffer to the hardware call either: |
670 | 670 | ||
671 | dma_sync_single_for_device(dev, dma_handle, size, direction); | 671 | dma_sync_single_for_device(dev, dma_handle, size, direction); |