linux-toradex.git/drivers/net/usb/asix_common.c, branch v4.9.90

net: asix: Avoid looping when the device does not respond

2016-10-14T20:06:54+00:00

Check answers from USB stack and avoid re-sending the request
multiple times if the device does not respond.

This fixes the following problem, observed with a probably flaky adapter.

[62108.732707] usb 1-3: new high-speed USB device number 5 using xhci_hcd
[62108.914421] usb 1-3: New USB device found, idVendor=0b95, idProduct=7720
[62108.914463] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[62108.914476] usb 1-3: Product: AX88x72A
[62108.914486] usb 1-3: Manufacturer: ASIX Elec. Corp.
[62108.914495] usb 1-3: SerialNumber: 000001
[62114.109109] asix 1-3:1.0 (unnamed net_device) (uninitialized):
	Failed to write reg index 0x0000: -110
[62114.109139] asix 1-3:1.0 (unnamed net_device) (uninitialized):
	Failed to send software reset: ffffff92
[62119.109048] asix 1-3:1.0 (unnamed net_device) (uninitialized):
	Failed to write reg index 0x0000: -110
...

Since the USB timeout is 5 seconds, and the operation is retried 30 times,
this results in

[62278.180353] INFO: task mtpd:1725 blocked for more than 120 seconds.
[62278.180373]       Tainted: G        W      3.18.0-13298-g94ace9e #1
[62278.180383] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
...
[62278.180957] kworker/2:0     D 0000000000000000     0  5744      2 0x00000000
[62278.180978] Workqueue: usb_hub_wq hub_event
[62278.181029]  ffff880177f833b8 0000000000000046 ffff88017fd00000 ffff88017b126d80
[62278.181048]  ffff880177f83fd8 ffff880065a71b60 0000000000013340 ffff880065a71b60
[62278.181065]  0000000000000286 0000000103b1c199 0000000000001388 0000000000000002
[62278.181081] Call Trace:
[62278.181092]  [] ? console_conditional_schedule+0x2c/0x2c
[62278.181105]  [] schedule+0x69/0x6b
[62278.181117]  [] schedule_timeout+0xe3/0x11d
[62278.181133]  [] ? trace_timer_start+0x51/0x51
[62278.181146]  [] do_wait_for_common+0x12f/0x16c
[62278.181162]  [] ? wake_up_process+0x39/0x39
[62278.181174]  [] wait_for_common+0x52/0x6d
[62278.181187]  [] wait_for_completion_timeout+0x13/0x15
[62278.181201]  [] usb_start_wait_urb+0x93/0xf1
[62278.181214]  [] usb_control_msg+0xe1/0x11d
[62278.181230]  [] usbnet_write_cmd+0x9c/0xc6 [usbnet]
[62278.181286]  [] asix_write_cmd+0x4e/0x7e [asix]
[62278.181300]  [] asix_set_sw_mii+0x25/0x4e [asix]
[62278.181314]  [] asix_mdio_read+0x51/0x109 [asix]
...

Signed-off-by: Guenter Roeck 
Signed-off-by: David S. Miller

net: asix: Avoid looping when the device is disconnected

2016-09-01T04:07:05+00:00

From: Vincent Palatin 

Check the answers from the USB stack and avoid re-sending multiple times
the request if the device has disappeared.

Signed-off-by: Vincent Palatin 
Signed-off-by: Robert Foss 
Tested-by: Robert Foss 
Signed-off-by: David S. Miller

net: asix: Add in_pm parameter

2016-09-01T04:07:05+00:00

From: Freddy Xin 

In order to R/W registers in suspend/resume functions, in_pm flags are
added to some functions to determine whether the nopm version of usb
functions is called.

Save BMCR and ANAR PHY registers in suspend function and restore them
in resume function.

Reset HW in resume function to ensure the PHY works correctly.

Signed-off-by: Freddy Xin 
Signed-off-by: Robert Foss 
Tested-by: Robert Foss 
Signed-off-by: David S. Miller

asix: Fix offset calculation in asix_rx_fixup() causing slow transmissions

2016-05-17T18:02:33+00:00

In testing with HiKey, we found that since
commit 3f30b158eba5 ("asix: On RX avoid creating bad Ethernet
frames"),
we're seeing lots of noise during network transfers:

[  239.027993] asix 1-1.1:1.0 eth0: asix_rx_fixup() Data Header synchronisation was lost, remaining 988
[  239.037310] asix 1-1.1:1.0 eth0: asix_rx_fixup() Bad Header Length 0x54ebb5ec, offset 4
[  239.045519] asix 1-1.1:1.0 eth0: asix_rx_fixup() Bad Header Length 0xcdffe7a2, offset 4
[  239.275044] asix 1-1.1:1.0 eth0: asix_rx_fixup() Data Header synchronisation was lost, remaining 988
[  239.284355] asix 1-1.1:1.0 eth0: asix_rx_fixup() Bad Header Length 0x1d36f59d, offset 4
[  239.292541] asix 1-1.1:1.0 eth0: asix_rx_fixup() Bad Header Length 0xaef3c1e9, offset 4
[  239.518996] asix 1-1.1:1.0 eth0: asix_rx_fixup() Data Header synchronisation was lost, remaining 988
[  239.528300] asix 1-1.1:1.0 eth0: asix_rx_fixup() Bad Header Length 0x2881912, offset 4
[  239.536413] asix 1-1.1:1.0 eth0: asix_rx_fixup() Bad Header Length 0x5638f7e2, offset 4

And network throughput ends up being pretty bursty and slow with
a overall throughput of at best ~30kB/s (where as previously we
got 1.1MB/s with the slower USB1.1 "full speed" host).

We found the issue also was reproducible on a x86_64 system,
using a "high-speed" USB2.0 port but the throughput did not
measurably drop (possibly due to the scp transfer being cpu
bound on my slow test hardware).

After lots of debugging, I found the check added in the
problematic commit seems to be calculating the offset
incorrectly.

In the normal case, in the main loop of the function, we do:
(where offset is zero, or set to "offset += (copy_length + 1) &
0xfffe" in the previous loop)
    rx->header = get_unaligned_le32(skb->data +
                                    offset);
    offset += sizeof(u32);

But the problematic patch calculates:
    offset = ((rx->remaining + 1) & 0xfffe) + sizeof(u32);
    rx->header = get_unaligned_le32(skb->data + offset);

Adding some debug logic to check those offset calculation used
to find rx->header, the one in problematic code is always too
large by sizeof(u32).

Thus, this patch removes the incorrect " + sizeof(u32)" addition
in the problematic calculation, and resolves the issue.

Cc: Dean Jenkins 
Cc: "David B. Robins" 
Cc: Mark Craske 
Cc: Emil Goode 
Cc: "David S. Miller" 
Cc: YongQin Liu 
Cc: Guodong Xu 
Cc: Ivan Vecera 
Cc: linux-usb@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: stable  #4.4+
Reported-by: Yongqin Liu 
Signed-off-by: John Stultz 
Signed-off-by: David S. Miller

asix: silence log message from oversize packet

2015-12-18T21:08:35+00:00

Since it is possible for an external system to send oversize packets
at anytime, it is best for driver not to print a message and spam
the log (potential external DoS).

Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=109471

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

drivers/net: get rid of unnecessary initializations in .get_drvinfo()

2015-10-16T07:24:10+00:00

Many drivers initialize uselessly n_priv_flags, n_stats, testinfo_len,
eedump_len & regdump_len fields in their .get_drvinfo() ethtool op.
It's not necessary as these fields is filled in ethtool_get_drvinfo().

v2: removed unused variable
v3: removed another unused variable

Signed-off-by: Ivan Vecera 
Signed-off-by: David S. Miller

asix: Continue processing URB if no RX netdev buffer

2015-10-05T13:58:43+00:00

Avoid a loss of synchronisation of the Ethernet Data header 32-bit
word due to a failure to get a netdev socket buffer.

The ASIX RX handling algorithm returned 0 upon a failure to get
an allocation of a netdev socket buffer. This causes the URB
processing to stop which potentially causes a loss of synchronisation
with the Ethernet Data header 32-bit word. Therefore, subsequent
processing of URBs may be rejected due to a loss of synchronisation.
This may cause additional good Ethernet frames to be discarded
along with outputting of synchronisation error messages.

Implement a solution which checks whether a netdev socket buffer
has been allocated before trying to copy the Ethernet frame into
the netdev socket buffer. But continue to process the URB so that
synchronisation is maintained. Therefore, only a single Ethernet
frame is discarded when no netdev socket buffer is available.

Signed-off-by: Dean Jenkins 
Signed-off-by: Mark Craske 
Signed-off-by: David S. Miller

asix: On RX avoid creating bad Ethernet frames

2015-10-05T13:58:43+00:00

When RX Ethernet frames span multiple URB socket buffers,
the data stream may suffer a discontinuity which will cause
the current Ethernet frame in the netdev socket buffer
to be incomplete. This frame needs to be discarded instead
of appending unrelated data from the current URB socket buffer
to the Ethernet frame in the netdev socket buffer. This avoids
creating a corrupted Ethernet frame in the netdev socket buffer.

A discontinuity can occur when the previous URB socket buffer
held an incomplete Ethernet frame due to truncation or a
URB socket buffer containing the end of the Ethernet frame
was missing.

Therefore, add a sanity test for when an Ethernet frame
spans multiple URB socket buffers to check that the remaining
bytes of the currently received Ethernet frame point to
a good Data header 32-bit word of the next Ethernet
frame. Upon error, reset the remaining bytes variable to
zero and discard the current netdev socket buffer.
Assume that the Data header is located at the start of
the current socket buffer and attempt to process the next
Ethernet frame from there. This avoids unnecessarily
discarding a good URB socket buffer that contains a new
Ethernet frame.

Signed-off-by: Dean Jenkins 
Signed-off-by: Mark Craske 
Signed-off-by: David S. Miller

asix: Simplify asix_rx_fixup_internal() netdev alloc

2015-10-05T13:58:41+00:00

The code is checking that the Ethernet frame will fit into a
netdev allocated socket buffer within the constraints of MTU size,
Ethernet header length plus VLAN header length.

The original code was checking rx->remaining each loop of the while
loop that processes multiple Ethernet frames per URB and/or Ethernet
frames that span across URBs. rx->remaining decreases per while loop
so there is no point in potentially checking multiple times that the
Ethernet frame (remaining part) will fit into the netdev socket buffer.

The modification checks that the size of the Ethernet frame will fit
the netdev socket buffer before allocating the netdev socket buffer.
This avoids grabbing memory and then deciding that the Ethernet frame
is too big and then freeing the memory.

Signed-off-by: Dean Jenkins 
Signed-off-by: Mark Craske 
Signed-off-by: David S. Miller

asix: Tidy-up 32-bit header word synchronisation

2015-10-05T13:58:40+00:00

Tidy-up the Data header 32-bit word synchronisation logic in
asix_rx_fixup_internal() by removing redundant logic tests.

The code is looking at the following cases of the Data header
32-bit word that is present before each Ethernet frame:

a) all 32 bits of the Data header word are in the URB socket buffer
b) first 16 bits of the Data header word are at the end of the URB
   socket buffer
c) last 16 bits of the Data header word are at the start of the URB
   socket buffer eg. split_head = true

Note that the lifetime of rx->split_head exists outside of the
function call and is accessed per processing of each URB. Therefore,
split_head being true acts on the next URB to be processed.

To check for b) the offset will be 16 bits (2 bytes) from the end of
the buffer then indicate split_head is true.
To check for c) split_head must be true because the first 16 bits
have been found.
To check for a) else c)

Note that the || logic of the old code included the state
(skb->len - offset == sizeof(u16) && rx->split_head) which is not
possible because the split_head cannot be true whilst checking for b).
This is because the split_head indicates that the first 16 bits have
been found and that is not possible whilst checking for the first 16
bits. Therefore simplify the logic.

Signed-off-by: Dean Jenkins 
Signed-off-by: Mark Craske 
Signed-off-by: David S. Miller