On 10/26/2012 04:23 PM, Seth Forshee wrote:
The brcmsmac internal tx buffering is problematic for a number of
reasons. The amount of buffering is excessive (228 packets in addition
to the 256 slots in each DMA ring), frames may be dropped due to a lack
of flow control, and the structure of the queues complicates the
otherwise straightforward mapping of mac80211 queues to device fifos.
This patch reworks the transmit code path to eliminate the internal
buffering. Frames are immediately handed off to the DMA support rather
than passing through an intermediate queue. ieee80211_(stop|wake)_queue()
are used for flow control to stop receiving frames when a DMA tx ring is
full.
To handle aggregation the concept of AMPDU sessions is added to the
driver. The AMPDU session allows MPDUs to be temporarily queued by the
DMA code until either a full AMPDU has been collected or circumstances
dictate that transmission should start with a partial AMPDU. The use of
a queue ensures that the tx headers are fully initialized before the
buffers are synced for DMA, and it allows non-aggregate frames to be
immediately placed in the tx ring so that more frames can be collected
for aggregation.
Signed-off-by: Seth Forshee <seth.forshee@xxxxxxxxxxxxx>
---
drivers/net/wireless/brcm80211/brcmsmac/ampdu.c | 666 ++++++++++-------------
drivers/net/wireless/brcm80211/brcmsmac/ampdu.h | 29 +-
drivers/net/wireless/brcm80211/brcmsmac/dma.c | 182 ++++++-
drivers/net/wireless/brcm80211/brcmsmac/dma.h | 9 +-
drivers/net/wireless/brcm80211/brcmsmac/main.c | 514 +++++------------
drivers/net/wireless/brcm80211/brcmsmac/main.h | 39 +-
drivers/net/wireless/brcm80211/brcmsmac/types.h | 1 -
7 files changed, 628 insertions(+), 812 deletions(-)
Hi Seth,
The idea behind the change is a good move. However, this change is quite
a overhaul especially for ampdu code. This makes it pretty hard to
review. At least against the previous implementation. So we still need
some time to chew on this one. We have been testing it and it looks good
there.
Could you somehow split this change into smaller steps?
Gr. Avs
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