No description
  • C 98.2%
  • Assembly 1%
  • Makefile 0.3%
  • Shell 0.2%
  • Python 0.1%
Find a file
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Martin Blumenstingl 80cd0b9748 net: stmmac: dwmac-meson8b: Fix the RGMII TX delay on Meson8b/8m2 SoCs
[ Upstream commit bd6f48546b9cb7a785344fc78058c420923d7ed8 ]

GXBB and newer SoCs use the fixed FCLK_DIV2 (1GHz) clock as input for
the m250_sel clock. Meson8b and Meson8m2 use MPLL2 instead, whose rate
can be adjusted at runtime.

So far we have been running MPLL2 with ~250MHz (and the internal
m250_div with value 1), which worked enough that we could transfer data
with an TX delay of 4ns. Unfortunately there is high packet loss with
an RGMII PHY when transferring data (receiving data works fine though).
Odroid-C1's u-boot is running with a TX delay of only 2ns as well as
the internal m250_div set to 2 - no lost (TX) packets can be observed
with that setting in u-boot.

Manual testing has shown that the TX packet loss goes away when using
the following settings in Linux (the vendor kernel uses the same
settings):
- MPLL2 clock set to ~500MHz
- m250_div set to 2
- TX delay set to 2ns on the MAC side

Update the m250_div divider settings to only accept dividers greater or
equal 2 to fix the TX delay generated by the MAC.

iperf3 results before the change:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec   182 MBytes   153 Mbits/sec  514      sender
[  5]   0.00-10.00  sec   182 MBytes   152 Mbits/sec           receiver

iperf3 results after the change (including an updated TX delay of 2ns):
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-10.00  sec   927 MBytes   778 Mbits/sec    0      sender
[  5]   0.00-10.01  sec   927 MBytes   777 Mbits/sec           receiver

Fixes: 4f6a71b84e ("net: stmmac: dwmac-meson8b: fix internal RGMII clock configuration")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-04 19:18:47 +01:00
arch powerpc: Fix __clear_user() with KUAP enabled 2020-01-04 19:18:37 +01:00
block iocost: over-budget forced IOs should schedule async delay 2019-12-31 16:46:19 +01:00
certs
crypto KEYS: asymmetric: return ENOMEM if akcipher_request_alloc() fails 2019-12-31 16:46:07 +01:00
Documentation dt-bindings: Improve validation build error handling 2020-01-04 19:18:11 +01:00
drivers net: stmmac: dwmac-meson8b: Fix the RGMII TX delay on Meson8b/8m2 SoCs 2020-01-04 19:18:47 +01:00
fs xfs: fix mount failure crash on invalid iclog memory access 2020-01-04 19:18:43 +01:00
include net/sched: add delete_empty() to filters and use it in cls_flower 2020-01-04 19:18:46 +01:00
init Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
ipc ipc/sem.c: convert to use built-in RCU list checking 2019-09-25 17:51:41 -07:00
kernel hrtimer: Annotate lockless access to timer->state 2020-01-04 19:18:41 +01:00
lib ubsan, x86: Annotate and allow __ubsan_handle_shift_out_of_bounds() in uaccess regions 2019-12-31 16:44:25 +01:00
LICENSES
mm mm: vmscan: protect shrinker idr replace with CONFIG_MEMCG 2019-12-31 16:46:07 +01:00
net net_sched: sch_fq: properly set sk->sk_pacing_status 2020-01-04 19:18:47 +01:00
samples samples: pktgen: fix proc_cmd command result check logic 2019-12-31 16:43:45 +01:00
scripts scripts/kallsyms: fix definitely-lost memory leak 2020-01-04 19:18:23 +01:00
security tomoyo: Don't use nifty names on sockets. 2020-01-04 19:18:42 +01:00
sound ASoC: soc-pcm: check symmetry before hw_params 2019-12-31 16:45:42 +01:00
tools selftests: vm: add fragment CONFIG_TEST_VMALLOC 2020-01-04 19:18:31 +01:00
usr kbuild: update compile-test header list for v5.4-rc2 2019-10-05 15:29:49 +09:00
virt KVM: arm/arm64: Properly handle faulting of device mappings 2019-12-31 16:46:24 +01:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap ARM: SoC fixes 2019-11-10 13:41:59 -08:00
COPYING
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild
Kconfig
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-22 14:28:14 -08:00
Makefile Linux 5.4.7 2019-12-31 16:46:36 +01:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.