linux-stable.git/drivers/net/ethernet/microchip, branch linux-5.11.y

lan743x: fix rx_napi_poll/interrupt ping-pong

2020-12-16T17:00:09+00:00

Even if there is more rx data waiting on the chip, the rx napi poll fn
will never run more than once - it will always read a few buffers, then
bail out and re-arm interrupts. Which results in ping-pong between napi
and interrupt.

This defeats the purpose of napi, and is bad for performance.

Fix by making the rx napi poll behave identically to other ethernet
drivers:
1. initialize rx napi polling with an arbitrary budget (64).
2. in the polling fn, return full weight if rx queue is not depleted,
   this tells the napi core to "keep polling".
3. update the rx tail ("ring the doorbell") once for every 8 processed
   rx ring buffers.

Thanks to Jakub Kicinski, Eric Dumazet and Andrew Lunn for their expert
opinions and suggestions.

Tested with 20 seconds of full bandwidth receive (iperf3):
        rx irqs      softirqs(NET_RX)
        -----------------------------
before  23827        33620
after   129          4081

Tested-by: Sven Van Asbroeck  # lan7430
Fixes: 23f0703c125be ("lan743x: Add main source files for new lan743x driver")
Signed-off-by: Sven Van Asbroeck 
Link: https://lore.kernel.org/r/20201215161954.5950-1-TheSven73@gmail.com
Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-12-12T06:29:38+00:00

xdp_return_frame_bulk() needs to pass a xdp_buff
to __xdp_return().

strlcpy got converted to strscpy but here it makes no
functional difference, so just keep the right code.

Conflicts:
	net/netfilter/nf_tables_api.c

Signed-off-by: Jakub Kicinski

ethernet: select CONFIG_CRC32 as needed

2020-12-04T22:42:21+00:00

A number of ethernet drivers require crc32 functionality to be
avaialable in the kernel, causing a link error otherwise:

arm-linux-gnueabi-ld: drivers/net/ethernet/agere/et131x.o: in function `et1310_setup_device_for_multicast':
et131x.c:(.text+0x5918): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/cadence/macb_main.o: in function `macb_start_xmit':
macb_main.c:(.text+0x4b88): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/faraday/ftgmac100.o: in function `ftgmac100_set_rx_mode':
ftgmac100.c:(.text+0x2b38): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/freescale/fec_main.o: in function `set_multicast_list':
fec_main.c:(.text+0x6120): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/freescale/fman/fman_dtsec.o: in function `dtsec_add_hash_mac_address':
fman_dtsec.c:(.text+0x830): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/freescale/fman/fman_dtsec.o:fman_dtsec.c:(.text+0xb68): more undefined references to `crc32_le' follow
arm-linux-gnueabi-ld: drivers/net/ethernet/netronome/nfp/nfpcore/nfp_hwinfo.o: in function `nfp_hwinfo_read':
nfp_hwinfo.c:(.text+0x250): undefined reference to `crc32_be'
arm-linux-gnueabi-ld: nfp_hwinfo.c:(.text+0x288): undefined reference to `crc32_be'
arm-linux-gnueabi-ld: drivers/net/ethernet/netronome/nfp/nfpcore/nfp_resource.o: in function `nfp_resource_acquire':
nfp_resource.c:(.text+0x144): undefined reference to `crc32_be'
arm-linux-gnueabi-ld: nfp_resource.c:(.text+0x158): undefined reference to `crc32_be'
arm-linux-gnueabi-ld: drivers/net/ethernet/nxp/lpc_eth.o: in function `lpc_eth_set_multicast_list':
lpc_eth.c:(.text+0x1934): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/rocker/rocker_ofdpa.o: in function `ofdpa_flow_tbl_do':
rocker_ofdpa.c:(.text+0x2e08): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/rocker/rocker_ofdpa.o: in function `ofdpa_flow_tbl_del':
rocker_ofdpa.c:(.text+0x3074): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/rocker/rocker_ofdpa.o: in function `ofdpa_port_fdb':
arm-linux-gnueabi-ld: drivers/net/ethernet/mellanox/mlx5/core/steering/dr_ste.o: in function `mlx5dr_ste_calc_hash_index':
dr_ste.c:(.text+0x354): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/microchip/lan743x_main.o: in function `lan743x_netdev_set_multicast':
lan743x_main.c:(.text+0x5dc4): undefined reference to `crc32_le'

Add the missing 'select CRC32' entries in Kconfig for each of them.

Signed-off-by: Arnd Bergmann 
Acked-by: Nicolas Ferre 
Acked-by: Madalin Bucur 
Acked-by: Mark Einon 
Acked-by: Simon Horman 
Link: https://lore.kernel.org/r/20201203232114.1485603-1-arnd@kernel.org
Signed-off-by: Jakub Kicinski

lan743x: replace polling loop by wait_event_timeout()

2020-11-25T00:14:04+00:00

The driver's ISR sends a 'software interrupt' event to the probe()
thread using the following method:
- probe(): write 0 to flag, enable s/w interrupt
- probe(): poll on flag, relax using usleep_range()
- ISR    : write 1 to flag

Replace with wake_up() / wait_event_timeout(). Besides being easier
to get right, this abstraction has better timing and memory
consistency properties.

Tested-by: Sven Van Asbroeck  # lan7430
Signed-off-by: Sven Van Asbroeck 
Link: https://lore.kernel.org/r/20201123191529.14908-2-TheSven73@gmail.com
Signed-off-by: Jakub Kicinski

lan743x: clean up software_isr function

2020-11-25T00:14:04+00:00

For no apparent reason, this function reads the INT_STS register, and
checks if the software interrupt bit is set. These things have already
been carried out by this function's only caller.

Clean up by removing the redundant code.

Tested-by: Sven Van Asbroeck  # lan7430
Signed-off-by: Sven Van Asbroeck 
Link: https://lore.kernel.org/r/20201123191529.14908-1-TheSven73@gmail.com
Signed-off-by: Jakub Kicinski

Merge https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-11-20T03:08:46+00:00

Signed-off-by: Jakub Kicinski

lan743x: replace devicetree phy parse code with library function

2020-11-17T18:46:20+00:00

The code in this driver which parses the devicetree to determine
the phy/fixed link setup, can be replaced by a single library
function: of_phy_get_and_connect().

Behaviour is identical, except that the library function will
complain when 'phy-connection-type' is omitted, instead of
blindly using PHY_INTERFACE_MODE_NA, which would result in an
invalid phy configuration.

The library function no longer brings out the exact phy_mode,
but the driver doesn't need this, because phy_interface_is_rgmii()
queries the phydev directly. Remove 'phy_mode' from the private
adapter struct.

While we're here, log info about the attached phy on connect,
this is useful because the phy type and connection method is now
fully configurable via the devicetree.

Tested on a lan7430 chip with built-in phy. Verified that adding
fixed-link/phy-connection-type in the devicetree results in a
fixed-link setup. Used ethtool to verify that the devicetree
settings are used.

Tested-by: Sven Van Asbroeck  # lan7430
Signed-off-by: Sven Van Asbroeck 
Reviewed-by: Andrew Lunn 
Link: https://lore.kernel.org/r/20201116170155.26967-1-TheSven73@gmail.com
Signed-off-by: Jakub Kicinski

lan743x: prevent entire kernel HANG on open, for some platforms

2020-11-14T23:25:12+00:00

On arm imx6, when opening the chip's netdev, the whole Linux
kernel intermittently hangs/freezes.

This is caused by a bug in the driver code which tests if pcie
interrupts are working correctly, using the software interrupt:

1. open: enable the software interrupt
2. open: tell the chip to assert the software interrupt
3. open: wait for flag
4. ISR: acknowledge s/w interrupt, set flag
5. open: notice flag, disable the s/w interrupt, continue

Unfortunately the ISR only acknowledges the s/w interrupt, but
does not disable it. This will re-trigger the ISR in a tight
loop.

On some (lucky) platforms, open proceeds to disable the s/w
interrupt even while the ISR is 'spinning'. On arm imx6,
the spinning ISR does not allow open to proceed, resulting
in a hung Linux kernel.

Fix minimally by disabling the s/w interrupt in the ISR, which
will prevent it from spinning. This won't break anything because
the s/w interrupt is used as a one-shot interrupt.

Note that this is a minimal fix, overlooking many possible
cleanups, e.g.:
- lan743x_intr_software_isr() is completely redundant and reads
  INT_STS twice for no apparent reason
- disabling the s/w interrupt in lan743x_intr_test_isr() is now
  redundant, but harmless
- waiting on software_isr_flag can be converted from a sleeping
  poll loop to wait_event_timeout()

Fixes: 23f0703c125b ("lan743x: Add main source files for new lan743x driver")
Tested-by: Sven Van Asbroeck  # arm imx6 lan7430
Signed-off-by: Sven Van Asbroeck 
Link: https://lore.kernel.org/r/20201112204741.12375-1-TheSven73@gmail.com
Signed-off-by: Jakub Kicinski

lan743x: fix issue causing intermittent kernel log warnings

2020-11-14T21:32:22+00:00

When running this chip on arm imx6, we intermittently observe
the following kernel warning in the log, especially when the
system is under high load:

[   50.119484] ------------[ cut here ]------------
[   50.124377] WARNING: CPU: 0 PID: 303 at kernel/softirq.c:169 __local_bh_enable_ip+0x100/0x184
[   50.132925] IRQs not enabled as expected
[   50.159250] CPU: 0 PID: 303 Comm: rngd Not tainted 5.7.8 #1
[   50.164837] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[   50.171395] [] (unwind_backtrace) from [] (show_stack+0x10/0x14)
[   50.179162] [] (show_stack) from [] (dump_stack+0xac/0xd8)
[   50.186408] [] (dump_stack) from [] (__warn+0xd0/0x10c)
[   50.193391] [] (__warn) from [] (warn_slowpath_fmt+0x98/0xc4)
[   50.200892] [] (warn_slowpath_fmt) from [] (__local_bh_enable_ip+0x100/0x184)
[   50.209860] [] (__local_bh_enable_ip) from [] (destroy_conntrack+0x48/0xd8 [nf_conntrack])
[   50.220038] [] (destroy_conntrack [nf_conntrack]) from [] (nf_conntrack_destroy+0x94/0x168)
[   50.230160] [] (nf_conntrack_destroy) from [] (skb_release_head_state+0xa0/0xd0)
[   50.239314] [] (skb_release_head_state) from [] (skb_release_all+0xc/0x24)
[   50.247946] [] (skb_release_all) from [] (consume_skb+0x74/0x17c)
[   50.255796] [] (consume_skb) from [] (lan743x_tx_release_desc+0x120/0x124)
[   50.264428] [] (lan743x_tx_release_desc) from [] (lan743x_tx_napi_poll+0x5c/0x18c)
[   50.273755] [] (lan743x_tx_napi_poll) from [] (net_rx_action+0x118/0x4a4)
[   50.282306] [] (net_rx_action) from [] (__do_softirq+0x13c/0x53c)
[   50.290157] [] (__do_softirq) from [] (irq_exit+0x150/0x17c)
[   50.297575] [] (irq_exit) from [] (__handle_domain_irq+0x60/0xb0)
[   50.305423] [] (__handle_domain_irq) from [] (gic_handle_irq+0x4c/0x90)
[   50.313790] [] (gic_handle_irq) from [] (__irq_usr+0x54/0x80)
[   50.321287] Exception stack(0xecd99fb0 to 0xecd99ff8)
[   50.326355] 9fa0:                                     1cf1aa74 00000001 00000001 00000000
[   50.334547] 9fc0: 00000001 00000000 00000000 00000000 00000000 00000000 00004097 b6d17d14
[   50.342738] 9fe0: 00000001 b6d17c60 00000000 b6e71f94 800b0010 ffffffff
[   50.349364] irq event stamp: 2525027
[   50.352955] hardirqs last  enabled at (2525026): [] net_rx_action+0xb4/0x4a4
[   50.360892] hardirqs last disabled at (2525027): [] _raw_spin_lock_irqsave+0x1c/0x50
[   50.369517] softirqs last  enabled at (2524660): [] __do_softirq+0x38c/0x53c
[   50.377446] softirqs last disabled at (2524693): [] irq_exit+0x150/0x17c
[   50.385027] ---[ end trace c0b571db4bc8087d ]---

The driver is calling dev_kfree_skb() from code inside a spinlock,
where h/w interrupts are disabled. This is forbidden, as documented
in include/linux/netdevice.h. The correct function to use
dev_kfree_skb_irq(), or dev_kfree_skb_any().

Fix by using the correct dev_kfree_skb_xxx() functions:

in lan743x_tx_release_desc():
  called by lan743x_tx_release_completed_descriptors()
    called by in lan743x_tx_napi_poll()
    which holds a spinlock
  called by lan743x_tx_release_all_descriptors()
    called by lan743x_tx_close()
    which can-sleep
conclusion: use dev_kfree_skb_any()

in lan743x_tx_xmit_frame():
  which holds a spinlock
conclusion: use dev_kfree_skb_irq()

in lan743x_tx_close():
  which can-sleep
conclusion: use dev_kfree_skb()

in lan743x_rx_release_ring_element():
  called by lan743x_rx_close()
    which can-sleep
  called by lan743x_rx_open()
    which can-sleep
conclusion: use dev_kfree_skb()

Fixes: 23f0703c125b ("lan743x: Add main source files for new lan743x driver")
Signed-off-by: Sven Van Asbroeck 
Link: https://lore.kernel.org/r/20201112185949.11315-1-TheSven73@gmail.com
Signed-off-by: Jakub Kicinski

Merge https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-11-13T00:54:48+00:00

Signed-off-by: Jakub Kicinski