Hello Marek
I have prepared a new set of patches, please take a look to them. The
series implements the coherent allocation, segments compaction and use
of sg_table, it does not implement the dma_map/dma_unmap/dma_sync, I
rather work on that one when you are back.
Thanks for your help
On Thu,
Hello,
On 7/17/2013 4:20 PM, Ricardo Ribalda Delgado wrote:
Hello again Marek
In my system I am doing the scatter gather compaction on device
driver... But I agree that it would be better done on the vb2 layer.
For the oversize sglist we could do one of this two things.
If we want to have a
Hello again:
I have started to implemt it, but I think there is more hidden work in
this task as it seems. In order to call dma_map_sg and
max_dma_segment_size I need acess to the struct device, but (correct
me if I am wrong), vb2 is device agnostic. Adding the above
functionality will mean not
Hello,
On 7/18/2013 9:39 AM, Ricardo Ribalda Delgado wrote:
Hello again:
I have started to implemt it, but I think there is more hidden work in
this task as it seems. In order to call dma_map_sg and
max_dma_segment_size I need acess to the struct device, but (correct
me if I am wrong), vb2 is
Hello,
On 7/15/2013 11:34 AM, Ricardo Ribalda Delgado wrote:
Most DMA engines have limitations regarding the number of DMA segments
(sg-buffers) that they can handle. Videobuffers can easily spread through
houndreds of pages.
In the previous aproach, the pages were allocated individually, this
Hi Marek
alloc_pages_exact returns pages of order 0, every single page is
filled into buf-pages, that then is used by vb2_dma_sg_mmap(), that
also expects order 0 pages (its loops increments in PAGE_SIZE). The
code has been tested on real HW.
Your concern is that that alloc_pages_exact splits
Hello,
On 7/17/2013 11:43 AM, Ricardo Ribalda Delgado wrote:
Hi Marek
alloc_pages_exact returns pages of order 0, every single page is
filled into buf-pages, that then is used by vb2_dma_sg_mmap(), that
also expects order 0 pages (its loops increments in PAGE_SIZE). The
code has been tested
Hello again
I have made some experiments and have replaced alloc_pages_exact with
alloc_pages of order N. Unfortunatelly vm_insert_page and vm_map_ram
does not work as expected.
vm_insert_page, only insert the PAGE_SIZE bytes of the higher order
page, if I try to add the other pages manually,
Hello again Marek
In my system I am doing the scatter gather compaction on device
driver... But I agree that it would be better done on the vb2 layer.
For the oversize sglist we could do one of this two things.
If we want to have a simple pass processing we have to allocate an
structure A for
Most DMA engines have limitations regarding the number of DMA segments
(sg-buffers) that they can handle. Videobuffers can easily spread through
houndreds of pages.
In the previous aproach, the pages were allocated individually, this
could led to the creation houndreds of dma segments
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