Hello Tomasz, Laurent,
I have printed some logs during the dmabuf export and attach for the SGT issue below. Please find it in the attachment. I hope it will be useful.
Regards, Subash
On 05/08/2012 04:45 PM, Subash Patel wrote:
Hi Laurent,
On 05/08/2012 02:44 PM, Laurent Pinchart wrote:
Hi Subash,
On Monday 07 May 2012 20:08:25 Subash Patel wrote:
Hello Thomasz, Laurent,
I found an issue in the function vb2_dc_pages_to_sgt() below. I saw that during the attach, the size of the SGT and size requested mis-matched (by atleast 8k bytes). Hence I made a small correction to the code as below. I could then attach the importer properly.
Thank you for the report.
Could you print the content of the sglist (number of chunks and size of each chunk) before and after your modifications, as well as the values of n_pages, offset and size ?
I will put back all the printk's and generate this. As of now, my setup has changed and will do this when I get sometime.
On 04/20/2012 08:15 PM, Tomasz Stanislawski wrote:
[snip]
+static struct sg_table *vb2_dc_pages_to_sgt(struct page **pages,
- unsigned int n_pages, unsigned long offset, unsigned long size)
+{
- struct sg_table *sgt;
- unsigned int chunks;
- unsigned int i;
- unsigned int cur_page;
- int ret;
- struct scatterlist *s;
- sgt = kzalloc(sizeof *sgt, GFP_KERNEL);
- if (!sgt)
- return ERR_PTR(-ENOMEM);
- /* compute number of chunks */
- chunks = 1;
- for (i = 1; i< n_pages; ++i)
- if (pages[i] != pages[i - 1] + 1)
- ++chunks;
- ret = sg_alloc_table(sgt, chunks, GFP_KERNEL);
- if (ret) {
- kfree(sgt);
- return ERR_PTR(-ENOMEM);
- }
- /* merging chunks and putting them into the scatterlist */
- cur_page = 0;
- for_each_sg(sgt->sgl, s, sgt->orig_nents, i) {
- unsigned long chunk_size;
- unsigned int j;
size = PAGE_SIZE;
- for (j = cur_page + 1; j< n_pages; ++j)
for (j = cur_page + 1; j< n_pages; ++j) {
- if (pages[j] != pages[j - 1] + 1)
- break;
size += PAGE }
- chunk_size = ((j - cur_page)<< PAGE_SHIFT) - offset;
- sg_set_page(s, pages[cur_page], min(size, chunk_size), offset);
[DELETE] size -= chunk_size;
- offset = 0;
- cur_page = j;
- }
- return sgt;
+}
Regards, Subash