linux_dsm_epyc7002/drivers/net/ethernet/amd/xgbe
Lendacky, Thomas 20a41fba67 amd-xgbe: Use wmb before updating current descriptor count
The code currently uses the lightweight dma_wmb barrier before updating
the current descriptor count. Under heavy load, the Tx cleanup routine
was seeing the updated current descriptor count before the updated
descriptor information. As a result, the Tx descriptor was being cleaned
up before it was used because it was not "owned" by the hardware yet,
resulting in a Tx queue hang.

Using the wmb barrier insures that the descriptor is updated before the
descriptor counter preventing the Tx queue hang. For extra insurance,
the Tx cleanup routine is changed to grab the current decriptor count on
entry and uses that initial value in the processing loop rather than
trying to chase the current value.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Tested-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-23 02:59:04 -07:00
..
Makefile amd-xgbe: Add traffic class support 2014-07-30 18:46:53 -07:00
xgbe-common.h amd-xgbe: Move the PHY support into amd-xgbe 2015-05-15 15:21:43 -04:00
xgbe-dcb.c amd-xgbe: Add netif_* message support to the driver 2015-05-15 15:21:43 -04:00
xgbe-debugfs.c amd-xgbe: Check for successful buffer allocation before use 2015-10-05 23:30:51 -07:00
xgbe-desc.c amd-xgbe: Fix DMA API debug warning 2015-07-08 15:57:14 -07:00
xgbe-dev.c amd-xgbe: Use wmb before updating current descriptor count 2015-10-23 02:59:04 -07:00
xgbe-drv.c amd-xgbe: Use wmb before updating current descriptor count 2015-10-23 02:59:04 -07:00
xgbe-ethtool.c amd-xgbe: Fix flow control setting logic 2015-05-15 15:21:43 -04:00
xgbe-main.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2015-06-24 16:49:49 -07:00
xgbe-mdio.c amd-xgbe: Add more netif_dbg output to the driver 2015-05-25 00:13:58 -04:00
xgbe-ptp.c ptp: xgbe: convert to the 64 bit get/set time methods. 2015-03-31 12:01:16 -04:00
xgbe.h treewide: fix typos in comment blocks 2015-08-07 14:46:24 +02:00