14 Feb
2013
14 Feb
'13
7:01 p.m.
Adrian Knoth wrote:
On Thu, Feb 14, 2013 at 06:46:30PM +0100, Clemens Ladisch wrote:
Would you say that the following is the proper way to allocate a DMA buffer used to hold level data?
err = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV_SG, snd_dma_pci_data(hdspm->pci), MADIFX_LEVEL_BUFFER_SIZE, &hdspm->dmaLevelBuffer);
hdspm->level_buffer = snd_sgbuf_get_ptr(&(hdspm->dmaLevelBuffer), 0);I don't see the code asking for the address of the second page, so I guess there isn't one.
Exactly.
So MADIFX_LEVEL_BUFFER_SIZE is guaranteed to not exceed the page size on all architectures?
Just to be sure: Takashi has recommended to use (u32*)dmaLevelBuffer.area. Even in the case of SG buffers, is this virtual address continuous and safe for memset?
Yes, the SG buffer's pages are vmap()ed there.
Regards, Clemens