linux-stable.git/drivers/net/ethernet/amazon, branch v5.5

net: ena: fix issues in setting interrupt moderation params in ethtool

2019-12-21T05:43:08+00:00

Issue 1:
--------
Reproduction steps:
1. sudo ethtool -C eth0 rx-usecs 128
2. sudo ethtool -C eth0 adaptive-rx on
3. sudo ethtool -C eth0 adaptive-rx off
4. ethtool -c eth0

expected output: rx-usecs 128
actual output: rx-usecs 0

Reason for issue:
In stage 3, ethtool userspace calls first the ena_get_coalesce() handler
to get the current value of all properties, and then the ena_set_coalesce()
handler. When ena_get_coalesce() is called the adaptive interrupt
moderation is still on. There is an if in the code that returns the
rx_coalesce_usecs only if the adaptive interrupt moderation is off.
And since it is still on, rx_coalesce_usecs is not set, meaning it
stays 0.

Solution to issue:
Remove this if static interrupt moderation intervals have nothing to do
with dynamic ones.

Issue 2:
--------
Reproduction steps:
1. sudo ethtool -C eth0 adaptive-rx on
2. sudo ethtool -C eth0 rx-usecs 128
3. ethtool -c eth0

expected output: rx-usecs 128
actual output: rx-usecs 0

Reason for issue:
In stage 2, when ena_set_coalesce() is called, the handler tests if
rx adaptive interrupt moderation is on, and if it is, it returns before
getting to the part in the function that sets the rx non-adaptive
interrupt moderation interval.

Solution to issue:
Remove the return from the function when rx adaptive interrupt moderation
is on.

Also cleaned up the fixed code in ena_set_coalesce by grouping together
adaptive interrupt moderation toggling, and using && instead of nested
ifs.

Fixes: b3db86dc4b82 ("net: ena: reimplement set/get_coalesce()")
Fixes: 0eda847953d8 ("net: ena: fix retrieval of nonadaptive interrupt moderation intervals")
Fixes: 1738cd3ed342 ("net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Arthur Kiyanovski 
Signed-off-by: David S. Miller

net: ena: fix default tx interrupt moderation interval

2019-12-21T05:43:08+00:00

Current default non-adaptive tx interrupt moderation interval is 196 us.
This value is too high and might cause the tx queue to fill up.

In this commit we set the default non-adaptive tx interrupt moderation
interval to 64 us in order to:
1. Reduce the probability of the queue filling-up (when compared to the
   current default value of 196 us).
2. Reduce unnecessary tx interrupt overhead (which happens if we set the
   default tx interval to 0).
   We determined experimentally that 64 us is an optimal value that
   reduces interrupt rate by more than 20% without affecting performance.

Fixes: 1738cd3ed342 ("net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Arthur Kiyanovski 
Signed-off-by: David S. Miller

net: ena: fix napi handler misbehavior when the napi budget is zero

2019-12-11T01:54:55+00:00

In netpoll the napi handler could be called with budget equal to zero.
Current ENA napi handler doesn't take that into consideration.

The napi handler handles Rx packets in a do-while loop.
Currently, the budget check happens only after decrementing the
budget, therefore the napi handler, in rare cases, could run over
MAX_INT packets.

In addition to that, this moves all budget related variables to int
calculation and stop mixing u32 to avoid ambiguity

Fixes: 1738cd3ed342 ("net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Netanel Belgazal 
Signed-off-by: David S. Miller

net: ena: ethtool: support set_channels callback

2019-10-07T13:30:03+00:00

Set channels callback enables the user to change the count of queues
used by the driver using ethtool. We decided to currently support only
equal number of rx and tx queues, this might change in the future.

Also rename dev_up to dev_was_up in ena_update_queue_count() to make
it clearer.

Signed-off-by: Sameeh Jubran 
Signed-off-by: David S. Miller

net: ena: remove redundant print of number of queues

2019-10-07T13:30:03+00:00

The number of queues can be derived using ethtool, no need to print
it in ena_probe()

Signed-off-by: Sameeh Jubran 
Signed-off-by: David S. Miller

net: ena: make ethtool -l show correct max number of queues

2019-10-07T13:30:03+00:00

- Update ena_ethtool:ena_get_channels() to return adapter->max_io_queues
  so that ethtool -l returns the correct maximum queue number.

- Change the name of ena_calc_io_queue_num() to
  ena_calc_max_io_queue_num() as it returns the maximum number of io
  queues and actual number of queues can be smaller if changed
  by ethtool -L which is implemented in a later commit.

- Change variable name from io_queue_num to max_num_io_queues in
  ena_calc_max_io_queue_num() and ena_probe().

- Make all types of variables that convey the number and sizeof queues
  to be u32, for consistency with the API between the driver and the
  device.

Signed-off-by: Arthur Kiyanovski 
Signed-off-by: Sameeh Jubran 
Signed-off-by: David S. Miller

net: ena: ethtool: get_channels: use combined only

2019-10-07T13:30:03+00:00

Since we use the same IRQ and NAPI to service RX and TX then we need to
use a combined channel instead of rx and tx channels.

Signed-off-by: Sameeh Jubran 
Signed-off-by: David S. Miller

net: ena: multiple queue creation related cleanups

2019-10-07T13:30:03+00:00

- Rename ena_calc_queue_size() to ena_calc_io_queue_size() for clarity
  and consistency
- Remove redundant number of io queues parameter in functions
  ena_enable_msix() and ena_enable_msix_and_set_admin_interrupts(),
  which already get adapter parameter, so use adapter->num_io_queues
  in the function instead.
- Use the local variable ena_dev instead of ctx->ena_dev in
  ena_calc_io_queue_size
- Fix multi row comment alignments

Signed-off-by: Arthur Kiyanovski 
Signed-off-by: Sameeh Jubran 
Signed-off-by: David S. Miller

net: ena: change num_queues to num_io_queues for clarity and consistency

2019-10-07T13:30:03+00:00

Most places in the code refer to the IO queues as io_queues and not
simply queues. Examples - max_io_queues_per_vf, ENA_MAX_NUM_IO_QUEUES,
ena_destroy_all_io_queues() etc..

We are also adding the new max_num_io_queues field to struct ena_adapter
in the following commit.

The changes included in this commit are:
struct ena_adapter->num_queues => struct ena_adapter->num_io_queues

Signed-off-by: Arthur Kiyanovski 
Signed-off-by: Sameeh Jubran 
Signed-off-by: David S. Miller

net: ena: clean up indentation issue

2019-09-27T18:32:02+00:00

There memset is indented incorrectly, remove the extraneous tabs.

Signed-off-by: Colin Ian King 
Signed-off-by: David S. Miller