[SRU][X/raspi2] Support for the RaspberryPi 3 B Plus board

Wed Aug 1 14:49:22 UTC 2018

BugLink: http://bugs.launchpad.net/bugs/1784025

Impact:

The RaspberryPi 3 B Plus[1] is the latest addition in the family of RaspberryPi
boards, and this patchset includes all the necessary bits (dts, lan driver and
wifi driver) to enable this board in our 4.4 Xenial raspi2 kernel.

How to test:

Build this kernel and boot a rpi3bplus with it: the board should boot fine, and
ethernet lan and wifi should work.

Regression potential:

To ease the regression analysis, we can logically split the patchset in 3
different set of patches.

1) the dts files (patches 0001 to 0006)

Patch 0001 contains the pi3bplus board dts files + the lan dts fragment - these
are new files, and don't modify any other dts in the tree.
Patches 0002 to 0005 are the fixup modifcation to make the above dts file work
in our 4.4 kernel.
Patch 006 is a fix for the bcm2708_common, a device tree used in every rpi board
dtb - it's a small fix, and the same modification is present in the 4.9+
Raspberry respository too (see
https://github.com/raspberrypi/linux/blob/rpi-4.9.y/arch/arm/boot/dts/bcm283x.dtsi
aroud lines 353-354) - unfortunately they squashed that fix, so i couldn't pick
the specific commit.

The only regression potential here is patch 0006, but since it's a small fix,
and it's even carried upstream, i mark it as low.

2) the lan driver (patches 0008 to 0018)

The rpi3bplus comes with a brand new gigabit capable ethernet adapter, driven by
the lan 7515 chip, a chip mainly used in usb to ethernet dongle. Unfortunately,
the lan7515 driver shipped in our Xenial tree was not working: the driver would
attach, the interface shows up, packets could be sent, but the host os never
received any input packets - sniffing the cable confirmed that the chip was
generating traffic and receiving reply packets too.

After some debugging i found that no interrupt was generated once packet
arrived, and that was due to upstream 23374573a899528a4b10d76276646f69b7ae1572
"lan78xx: Correctly indicate invalid OTP", reverting this would bring my
ethernet back to life (patch 0008).

"lan78xx: Correctly indicate invalid OTP" originated around 4.17, way after a
complete overhaul of the phy code wad done for all the usbnet driver - after
more debugging i found that the 4.4 driver ships a workaround to enable phy
interrupts (see lan78xx_open()), so i'm thinking there's some correlation
between the phy overhaul and this commit, but without the datasheet i can't tell
what those bits in that register are actually doing - for now i just reverted
this patch locally and made the driver work again.

All the other patches (0009 to 0018) are backports of features added to the
driver by the Raspberry Foundation to make the driver better integrate in a dts
environment.

There's literally no regression potential here, since the driver was not working
in the first place, (and i actually made it work again).

3) the wifi driver (patches 0019 to 0026)

The wifi chip used in the rpi3bplus is very different from the one used in the
original rpi3 board (Broadcom BCM43438 vs Cypress CYW43455), but it uses the
same driver and i had to backport several fixes from upstream to make it work:
all the commits fix isolated bugs, and can be easily reviewed.

There's some regression potential here, but all code comes from upstream fixes,
so i mark it as low.

When possible i picked up the upstream version of the same patch (instead of the
one carried in the RaspberryPi branch - https://github.com/raspberrypi/linux
rpi-4.9.y), and except for these 6 commits:

"BCM270X_DT: Add Pi 3+ dts files"
"lan78xx: Enable LEDs if no valid EEPROM or OTP"
"lan78xx: Read initial EEE status from DT"
"lan78xx: Change LEDs to include 10Mb activity"
"lan78xx: Ignore DT MAC address if already valid"
"lan78xx: Move enabling of EEE into PHY init code"

all the remaining patches (20 out of 26) came from upstream - patches marked
with 'cherry-picked...' are clean cherry picks, while the one with
'backported...' required a varying degree of rework to make it apply (and
work).

I'm proposing this for inclusion in the Xenial raspi2 kernel.

1: https://www.raspberrypi.org/blog/raspberry-pi-3-model-bplus-sale-now-35/

------------------------------------------------------------------------------

The following changes since commit a9108920671adf3c81eb1cf5f35586c831b4b94a:

  UBUNTU: Ubuntu-raspi2-4.4.0-1092.100 (2018-06-12 21:35:39 +0000)

are available in the git repository at:

  git://git.launchpad.net/~p-pisati/ubuntu/+source/linux x-raspi2-3bplus

for you to fetch changes up to b2af40a9594d86d39206e7c909de0134cc516933:

  brcmfmac: sdio: Increase the default timeouts a bit (2018-08-01 12:43:49 +0200)

----------------------------------------------------------------
Alexander Graf (1):
      lan78xx: Connect phy early

Dave Stevenson (1):
      net: lan78xx: Allow for VLAN headers in timeout.

Hante Meuleman (2):
      brcmfmac: Disable runtime pm for USB.
      brcmfmac: Return actual error by fwil.

Paolo Pisati (12):
      UBUNTU: SAUCE: dts: remove i2c_dsi reference (4.9+ only)
      UBUNTU: SAUCE: dts: use 0 instead of GPIO_ACTIVE_LOW
      UBUNTU: SAUCE: dts: remove the hdmi node since it's part of the vc4 overlay
      UBUNTU: SAUCE: dts: use the virtgpio driver
      UBUNTU: SAUCE: fix address & size of reg cell for usb1
      UBUNTU: modules: remove lan78xx and microchip phy check
      UBUNTU: SAUCE: Revert "lan78xx: Correctly indicate invalid OTP"
      brcmfmac: Fix double free on exception at module load.
      brcmfmac: only lock and unlock fws if fws is not null
      brcmfmac: Fix warn trace on module unload while in ibss mode
      brcmfmac: fix p2p scan abort null pointer exception
      brcmf: Fix null pointer exception in bcdc_hdrpull

Phil Elwell (9):
      BCM270X_DT: Add Pi 3+ dts files
      lan78xx: Read MAC address from DT if present
      lan78xx: Enable LEDs if no valid EEPROM or OTP
      lan78xx: Read initial EEE status from DT
      lan78xx: Change LEDs to include 10Mb activity
      lan78xx: Read LED states from Device Tree
      lan78xx: Ignore DT MAC address if already valid
      lan78xx: Don't reset the interface on open
      lan78xx: Move enabling of EEE into PHY init code

Sjoerd Simons (1):
      brcmfmac: sdio: Increase the default timeouts a bit

 arch/arm/boot/dts/Makefile                         |   1 +
 arch/arm/boot/dts/bcm2708_common.dtsi              |   2 +
 arch/arm/boot/dts/bcm2710-rpi-3-b-plus.dts         | 210 +++++++++++++++++++++
 arch/arm/boot/dts/bcm283x-rpi-lan7515.dtsi         |  36 ++++
 arch/arm/boot/dts/overlays/README                  |   8 +
 .../abi/4.4.0-1091.99/armhf/raspi2.modules         |   2 -
 drivers/net/usb/lan78xx.c                          | 108 ++++++++---
 drivers/net/wireless/brcm80211/brcmfmac/bcdc.c     |   3 +-
 drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c |   9 +-
 drivers/net/wireless/brcm80211/brcmfmac/core.c     |   2 +
 drivers/net/wireless/brcm80211/brcmfmac/fwil.c     |   3 +-
 drivers/net/wireless/brcm80211/brcmfmac/fwsignal.c |   7 +-
 drivers/net/wireless/brcm80211/brcmfmac/p2p.c      |   2 +-
 drivers/net/wireless/brcm80211/brcmfmac/sdio.c     |   4 +-
 drivers/net/wireless/brcm80211/brcmfmac/usb.c      |   1 -
 15 files changed, 360 insertions(+), 38 deletions(-)
 create mode 100644 arch/arm/boot/dts/bcm2710-rpi-3-b-plus.dts
 create mode 100644 arch/arm/boot/dts/bcm283x-rpi-lan7515.dtsi
-- 
bye,
p.