iwlegacy: fix enqueue hcmd race conditions
We mark command as huge by using meta->flags from other (non huge) command,
but flags can be possibly overridden, when non huge command is enqueued,
what can lead to:
WARNING: at lib/dma-debug.c:696 dma_debug_device_change+0x1a3/0x1f0()
DMA-API: device driver has pending DMA allocations while released from device [count=1]
To fix introduce additional CMD_MAPPED to mark command as mapped and
serialize iwl_enqueue_hcmd() with iwl_tx_cmd_complete() using
hcmd_lock. Serialization will also fix possible race conditions,
because q->read_ptr, q->write_ptr are modified/used in parallel.
Do not change callback, I did (and fixed) that mistake in iwlagn.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlegacy/iwl-dev.h b/drivers/net/wireless/iwlegacy/iwl-dev.h
index 36c01aa..df19d5c 100644
--- a/drivers/net/wireless/iwlegacy/iwl-dev.h
+++ b/drivers/net/wireless/iwlegacy/iwl-dev.h
@@ -290,6 +290,7 @@
CMD_SIZE_HUGE = (1 << 0),
CMD_ASYNC = (1 << 1),
CMD_WANT_SKB = (1 << 2),
+ CMD_MAPPED = (1 << 3),
};
#define DEF_CMD_PAYLOAD_SIZE 320