Hi Laurent,
On 01/20/2012 04:12 PM, Laurent Pinchart wrote:
Hi Tomasz,
On Friday 20 January 2012 11:58:39 Tomasz Stanislawski wrote:
On 01/20/2012 11:41 AM, Sumit Semwal wrote:
On 20 January 2012 00:37, Pawel Osciak<pawel@xxxxxxxxxx> wrote:
Hi Sumit,
Thank you for your work. Please find my comments below.
Hi Pawel,
<snip>
struct vb2_mem_ops {
void *(*alloc)(void *alloc_ctx, unsigned long size);
@@ -65,6 +82,16 @@ struct vb2_mem_ops {
unsigned long size, int write);
void (*put_userptr)(void *buf_priv);
+ /* Comment from Rob Clark: XXX: I think the attach / detach
could be handled + * in the vb2 core, and vb2_mem_ops really
just need to get/put the + * sglist (and make sure that the
sglist fits it's needs..) + */
I *strongly* agree with Rob here. Could you explain the reason behind
not doing this?
Allocator should ideally not have to be aware of attaching/detaching,
this is not specific to an allocator.
Ok, I thought we'll start with this version first, and then refine.
But you guys are right.
I think that it is not possible to move attach/detach to vb2-core. The
problem is that dma_buf_attach needs 'struct device' argument. This
pointer is not available in vb2-core. This pointer is delivered by
device's driver in "void *alloc_context".
Moving information about device would introduce new problems like:
- breaking layering in vb2
- some allocators like vb2-vmalloc do not posses any device related
attributes
What about passing the device to vb2-core then ?
IMO, One way to do this is adding field 'struct device *dev' to struct
vb2_queue. This field should be filled by a driver prior to calling
vb2_queue_init.
Regards,
Tomasz Stanislawski
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