On 09/28/2016 02:11 PM, David Rientjes wrote:
On Tue, 27 Sep 2016, Ben Greear wrote:
I have been running this patch for a while:
ath10k: Use GPF_DMA32 for firmware swap memory.
This fixes OS crash when using QCA 9984 NIC on x86-64 system
without vt-d enabled.
Also tested on ea8500 with 9980, and x86-64 with 9980 and 9880.
All tests were with CT firmware.
Signed-off-by: Ben Greear <gree...@candelatech.com>
-------------------- drivers/net/wireless/ath/ath10k/wmi.c
--------------------
index e20aa39..727b3aa 100644
@@ -4491,7 +4491,7 @@ static int ath10k_wmi_alloc_chunk(struct ath10k *ar, u32
req_id,
if (!pool_size)
return -EINVAL;
- vaddr = kzalloc(pool_size, GFP_KERNEL | __GFP_NOWARN);
+ vaddr = kzalloc(pool_size, GFP_KERNEL | __GFP_NOWARN | GFP_DMA32);
if (!vaddr)
num_units /= 2;
}
It sometimes works, on some systems, but then it also often fails with the
splat
below, especially with several NICs in the system.
I suppose it's failing sometimes because the BUG() will trigger when
trying to allocate new slab or CONFIG_ZONE_DMA32 isn't configured. That
shouldn't panic the kernel anymore since commit 72baeef0c271 ("slab: do
not panic on invalid gfp_mask") in 4.8, but you shouldn't be doing
kzalloc(..., ... | GFP_DMA32) anyway.
CONFIG_ZONE_DMA32 is enabled in my .config.
pool_size is relatively large (maybe 256k or so).
If it's 256k, why allocate through the slab allocator? Why not
alloc_pages(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO | __GFP_NOWARN,
get_order(pool_size))?
I really don't understand the (subtle?) difference between alloc_pages and
kzalloc,
but I will give your suggestion a try and see if it works. If you have time,
maybe you could take
a look at drivers/net/wireless/ath/ath10k/wmi.c in the ath10k_wmi_alloc_chunk
method
to see if you notice any problems with using alloc_pages there?
Thanks for the suggestion.
--
Ben Greear <gree...@candelatech.com>
Candela Technologies Inc http://www.candelatech.com
