linux/drivers/net/sfc, branch v3.0.79

sfc: Only use TX push if a single descriptor is to be written

2013-03-28T19:06:01Z

[ Upstream commit fae8563b25f73dc584a07bcda7a82750ff4f7672 ] Using TX push when notifying the NIC of multiple new descriptors in the ring will very occasionally cause the TX DMA engine to re-use an old descriptor. This can result in a duplicated or partly duplicated packet (new headers with old data), or an IOMMU page fault. This does not happen when the pushed descriptor is the only one written. TX push also provides little latency benefit when a packet requires more than one descriptor. Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

sfc: Disable soft interrupt handling during efx_device_detach_sync()

2013-03-28T19:06:01Z

[ Upstream commit 35205b211c8d17a8a0b5e8926cb7c73e9a7ef1ad ] efx_device_detach_sync() locks all TX queues before marking the device detached and thus disabling further TX scheduling. But it can still be interrupted by TX completions which then result in TX scheduling in soft interrupt context. This will deadlock when it tries to acquire a TX queue lock that efx_device_detach_sync() already acquired. To avoid deadlock, we must use netif_tx_{,un}lock_bh(). Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

sfc: Detach net device when stopping queues for reconfiguration

2013-03-28T19:06:01Z

[ Upstream commit 29c69a4882641285a854d6d03ca5adbba68c0034 ] We must only ever stop TX queues when they are full or the net device is not 'ready' so far as the net core, and specifically the watchdog, is concerned. Otherwise, the watchdog may fire *immediately* if no packets have been added to the queue in the last 5 seconds. The device is ready if all the following are true: (a) It has a qdisc (b) It is marked present (c) It is running (d) The link is reported up (a) and (c) are normally true, and must not be changed by a driver. (d) is under our control, but fake link changes may disturb userland. This leaves (b). We already mark the device absent during reset and self-test, but we need to do the same during MTU changes and ring reallocation. We don't need to do this when the device is brought down because then (c) is already false. Signed-off-by: Ben Hutchings [bwh: Backported to 3.0: adjust context] Signed-off-by: Greg Kroah-Hartman

sfc: Fix efx_rx_buf_offset() in the presence of swiotlb

2013-03-28T19:06:01Z

[ Upstream commits 06e63c57acbb1df7c35ebe846ae416a8b88dfafa, b590ace09d51cd39744e0f7662c5e4a0d1b5d952 and c73e787a8db9117d59b5180baf83203a42ecadca ] We assume that the mapping between DMA and virtual addresses is done on whole pages, so we can find the page offset of an RX buffer using the lower bits of the DMA address. However, swiotlb maps in units of 2K, breaking this assumption. Add an explicit page_offset field to struct efx_rx_buffer. Signed-off-by: Ben Hutchings [bwh: Backported to 3.0: adjust context] Signed-off-by: Greg Kroah-Hartman

sfc: Properly sync RX DMA buffer when it is not the last in the page

2013-03-28T19:06:01Z

[ Upstream commit 3a68f19d7afb80f548d016effbc6ed52643a8085 ] We may currently allocate two RX DMA buffers to a page, and only unmap the page when the second is completed. We do not sync the first RX buffer to be completed; this can result in packet loss or corruption if the last RX buffer completed in a NAPI poll is the first in a page and is not DMA-coherent. (In the middle of a NAPI poll, we will handle the following RX completion and unmap the page *before* looking at the content of the first buffer.) Signed-off-by: Ben Hutchings [bwh: Backported to 3.0: adjust context] Signed-off-by: Greg Kroah-Hartman

sfc: Fix timekeeping in efx_mcdi_poll()

2013-03-28T19:06:01Z

[ Upstream commit ebf98e797b4e26ad52ace1511a0b503ee60a6cd4 ] efx_mcdi_poll() uses get_seconds() to read the current time and to implement a polling timeout. The use of this function was chosen partly because it could easily be replaced in a co-sim environment with a macro that read the simulated time. Unfortunately the real get_seconds() returns the system time (real time) which is subject to adjustment by e.g. ntpd. If the system time is adjusted forward during a polled MCDI operation, the effective timeout can be shorter than the intended 10 seconds, resulting in a spurious failure. It is also possible for a backward adjustment to delay detection of a areal failure. Use jiffies instead, and change MCDI_RPC_TIMEOUT to be denominated in jiffies. Also correct rounding of the timeout: check time > finish (or rather time_after(time, finish)) and not time >= finish. Signed-off-by: Ben Hutchings [bwh: Backported to 3.0: adjust context] Signed-off-by: Greg Kroah-Hartman

sfc: lock TX queues when calling netif_device_detach()

2013-03-28T19:06:00Z

[ Upstream commit c2f3b8e3a44b6fe9e36704e30157ebe1a88c08b1 ] The assertion of netif_device_present() at the top of efx_hard_start_xmit() may fail if we don't do this. Signed-off-by: Ben Hutchings [bwh: Backported to 3.0: adjust context] Signed-off-by: Greg Kroah-Hartman

sfc: Fix two causes of flush failure

2013-03-28T19:06:00Z

[ Upstream commits a606f4325dca6950996abbae452d33f2af095f39, d5e8cc6c946e0857826dcfbb3585068858445bfe, 525d9e824018cd7cc8d8d44832ddcd363abfe6e1 ] The TX DMA engine issues upstream read requests when there is room in the TX FIFO for the completion. However, the fetches for the rest of the packet might be delayed by any back pressure. Since a flush must wait for an EOP, the entire flush may be delayed by back pressure. Mitigate this by disabling flow control before the flushes are started. Since PF and VF flushes run in parallel introduce fc_disable, a reference count of the number of flushes outstanding. The same principle could be applied to Falcon, but that would bring with it its own testing. We sometimes hit a "failed to flush" timeout on some TX queues, but the flushes have completed and the flush completion events seem to go missing. In this case, we can check the TX_DESC_PTR_TBL register and drain the queues if the flushes had finished. Signed-off-by: Ben Hutchings [bwh: Backported to 3.0: - Call efx_nic_type::finish_flush() on both success and failure paths - Check the TX_DESC_PTR_TBL registers in the polling loop - Declare efx_mcdi_set_mac() extern] Signed-off-by: Greg Kroah-Hartman

sfc: Convert firmware subtypes to native byte order in efx_mcdi_get_board_cfg()

2013-03-28T19:06:00Z

[ Upstream commit bfeed902946a31692e7a24ed355b6d13ac37d014 ] On big-endian systems the MTD partition names currently have mangled subtype numbers and are not recognised by the firmware update tool (sfupdate). Signed-off-by: Ben Hutchings [bwh: Backported to 3.0: use old macros for length of firmware subtype array] Signed-off-by: Greg Kroah-Hartman

sfc: Do not attempt to flush queues if DMA is disabled

2013-03-28T19:06:00Z

[ Upstream commit 3dca9d2dc285faf1910d405b65df845cab061356 ] efx_nic_fatal_interrupt() disables DMA before scheduling a reset. After this, we need not and *cannot* flush queues. Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman