Messages in this thread | | | Date | Tue, 29 Apr 2008 18:37:38 -0600 | From | Grant Grundler <> | Subject | Re: [patch v3] doc: DMA-mapping.txt has undeclared variables [Bug 10397] |
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On Mon, Apr 28, 2008 at 05:58:49AM -0700, Matti Linnanvuori wrote: > From: Matti Linnanvuori <mattilinnanvuori@yahoo.com> > > Consistently use pdev as the variable of type struct pci_dev *. > Update DMA mapping documentation to use 'pdev' rather than 'dev' in > example code that calls routines expecting 'struct pci_device *', since 'dev' > might make readers think they're passing 'struct device *' parameters. > Bug 10397. > > Signed-off-by: Matti Linnanvuori <mattilinnanvuori@yahoo.com>
Acked-by: Grant Grundler <grundler@parisc-linux.org>
Thanks! grant
> > --- > > --- linux-2.6/Documentation/DMA-mapping.txt 2008-03-23 09:01:06.304511500 +0200 > +++ linux/Documentation/DMA-mapping.txt 2008-04-06 06:56:11.821314500 +0300 > @@ -315,9 +315,9 @@ > > dma_addr_t dma_handle; > > - cpu_addr = pci_alloc_consistent(dev, size, &dma_handle); > + cpu_addr = pci_alloc_consistent(pdev, size, &dma_handle); > > -where dev is a struct pci_dev *. You should pass NULL for PCI like buses > +where pdev is a struct pci_dev *. You should pass NULL for PCI like buses > where devices don't have struct pci_dev (like ISA, EISA). This may be > called in interrupt context. > > @@ -354,9 +354,9 @@ > > To unmap and free such a DMA region, you call: > > - pci_free_consistent(dev, size, cpu_addr, dma_handle); > + pci_free_consistent(pdev, size, cpu_addr, dma_handle); > > -where dev, size are the same as in the above call and cpu_addr and > +where pdev, size are the same as in the above call and cpu_addr and > dma_handle are the values pci_alloc_consistent returned to you. > This function may not be called in interrupt context. > > @@ -371,9 +371,9 @@ > > struct pci_pool *pool; > > - pool = pci_pool_create(name, dev, size, align, alloc); > + pool = pci_pool_create(name, pdev, size, align, alloc); > > -The "name" is for diagnostics (like a kmem_cache name); dev and size > +The "name" is for diagnostics (like a kmem_cache name); pdev and size > are as above. The device's hardware alignment requirement for this > type of data is "align" (which is expressed in bytes, and must be a > power of two). If your device has no boundary crossing restrictions, > @@ -472,11 +472,11 @@ > void *addr = buffer->ptr; > size_t size = buffer->len; > > - dma_handle = pci_map_single(dev, addr, size, direction); > + dma_handle = pci_map_single(pdev, addr, size, direction); > > and to unmap it: > > - pci_unmap_single(dev, dma_handle, size, direction); > + pci_unmap_single(pdev, dma_handle, size, direction); > > You should call pci_unmap_single when the DMA activity is finished, e.g. > from the interrupt which told you that the DMA transfer is done. > @@ -493,17 +493,17 @@ > unsigned long offset = buffer->offset; > size_t size = buffer->len; > > - dma_handle = pci_map_page(dev, page, offset, size, direction); > + dma_handle = pci_map_page(pdev, page, offset, size, direction); > > ... > > - pci_unmap_page(dev, dma_handle, size, direction); > + pci_unmap_page(pdev, dma_handle, size, direction); > > Here, "offset" means byte offset within the given page. > > With scatterlists, you map a region gathered from several regions by: > > - int i, count = pci_map_sg(dev, sglist, nents, direction); > + int i, count = pci_map_sg(pdev, sglist, nents, direction); > struct scatterlist *sg; > > for_each_sg(sglist, sg, count, i) { > @@ -527,7 +527,7 @@ > > To unmap a scatterlist, just call: > > - pci_unmap_sg(dev, sglist, nents, direction); > + pci_unmap_sg(pdev, sglist, nents, direction); > > Again, make sure DMA activity has already finished. > > @@ -550,11 +550,11 @@ > So, firstly, just map it with pci_map_{single,sg}, and after each DMA > transfer call either: > > - pci_dma_sync_single_for_cpu(dev, dma_handle, size, direction); > + pci_dma_sync_single_for_cpu(pdev, dma_handle, size, direction); > > or: > > - pci_dma_sync_sg_for_cpu(dev, sglist, nents, direction); > + pci_dma_sync_sg_for_cpu(pdev, sglist, nents, direction); > > as appropriate. > > @@ -562,7 +562,7 @@ > finish accessing the data with the cpu, and then before actually > giving the buffer to the hardware call either: > > - pci_dma_sync_single_for_device(dev, dma_handle, size, direction); > + pci_dma_sync_single_for_device(pdev, dma_handle, size, direction); > > or: > > @@ -739,7 +739,7 @@ > > dma_addr_t dma_handle; > > - dma_handle = pci_map_single(dev, addr, size, direction); > + dma_handle = pci_map_single(pdev, addr, size, direction); > if (pci_dma_mapping_error(dma_handle)) { > /* > * reduce current DMA mapping usage, > > > > ____________________________________________________________________________________ > Be a better friend, newshound, and > know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ
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