mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-08-27 03:10:12 +00:00
Code Issues Releases Wiki Activity

ioat3: fix p-disabled q-continuation

Browse source 
When continuing a pq calculation the driver needs 3 extra sources.  The
driver can perform a 3 source calculation with a single descriptor, but
needs an extended descriptor to process up to 8 sources in one
operation.  However, in the p-disabled case only one extra source is
needed.  When continuing a p-disabled operation there are occasions
(i.e. 0 < src_cnt % 8 < 3) where the tail operation does not need an
extended descriptor.  Properly account for this fact otherwise invalid
'dmacount' values will be written to hardware usually causing the
channel to halt with 'invalid descriptor' errors.

Cc: <stable@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams 2009-12-17 13:52:39 -07:00
parent 22763c5cf3
commit cd78809f61
1 changed files with 4 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
drivers/dma/ioat/dma_v3.c
View file

@ -650,9 +650,11 @@ __ioat3_prep_pq_lock(struct dma_chan *c, enum sum_check_flags *result,
num_descs = ioat2_xferlen_to_descs(ioat, len);
/* we need 2x the number of descriptors to cover greater than 3
* sources
* sources (we need 1 extra source in the q-only continuation
* case and 3 extra sources in the p+q continuation case.
*/
if (src_cnt > 3 || flags & DMA_PREP_CONTINUE) {
if (src_cnt + dmaf_p_disabled_continue(flags) > 3 ||
(dmaf_continue(flags) && !dmaf_p_disabled_continue(flags))) {
with_ext = 1;
num_descs *= 2;
} else