Re: [PATCH 0/2] irq-meson-gpio: make it possible to build as a module

From: Marc Zyngier
Date: Mon Oct 26 2020 - 14:30:20 EST

On 2020-10-26 17:28, Kevin Hilman wrote:
Marc Zyngier <maz@xxxxxxxxxx> writes:

On 2020-10-26 16:18, Kevin Hilman wrote:
Marc Zyngier <maz@xxxxxxxxxx> writes:

On Tue, 20 Oct 2020 08:25:30 +0100,
Neil Armstrong <narmstrong@xxxxxxxxxxxx> wrote:

In order to reduce the kernel Image size on multi-platform
distributions,
make it possible to build the Amlogic GPIO IRQ controller as a module
by switching it to a platform driver.

The second patch removes MESON_IRQ_GPIO selection from ARCH_MESON to
allow
building the driver as module.

Neil Armstrong (2):
irqchip: irq-meson-gpio: make it possible to build as a module
arm64: meson: remove MESON_IRQ_GPIO selection

arch/arm64/Kconfig.platforms | 1 -
drivers/irqchip/Kconfig | 5 +-
drivers/irqchip/irq-meson-gpio.c | 89
++++++++++++++++++++------------
3 files changed, 59 insertions(+), 36 deletions(-)

I've tried this series on my vim3l with the this driver compiled as a
module, and lost the Ethernet interface in the process, as the phy
wasn't able to resolve its interrupt and things fail later on:

[ 72.238291] meson8b-dwmac ff3f0000.ethernet eth1: no phy at addr -1
[ 72.238917] meson8b-dwmac ff3f0000.ethernet eth1: stmmac_open:
Cannot attach to PHY (error: -19)

This is a generic problem with making DT-based interrupt controllers
modular when not *all* the drivers can deal with probing deferral.

Yes, but this series still keeps the default as built-in.

If you build as a module, and you add `fw_devlink=on` to the kernel
command-line, device-links will be created based on DT dependencies
which will ensure the right module load order.

It doesn't work here. I get the exact same error (well, with eth0
instead
of eth1). In my experience, fw_devlink isn't reliable yet. Config on
request.

Other than CONFIG_MESON_IRQ_GPIO=m, are you using default upstream
defconfig?

I use something that is much closer to a Debian configuration, given that
the same kernel as to run on *all* the systems I have access to.

I just double-checked with this series on top of v5.10-rc1, and I have
eth0 working with interrupts without needing fw_devlink=on.

With the default upstream defconfig all the networking for these devices
is already configured as modules.

dmesg: http://www.loen.fr/tmp/dmesg
config: http://www.loen.fr/tmp/Config.full-arm64

root@tiger-roach:~# lsmod
Module Size Used by
macvtap 16384 0
macvlan 32768 1 macvtap
tap 32768 1 macvtap
nls_ascii 16384 1
nls_cp437 20480 1
vfat 28672 1
fat 81920 1 vfat
aes_ce_blk 36864 0
crypto_simd 24576 1 aes_ce_blk
cryptd 28672 1 crypto_simd
aes_ce_cipher 20480 1 aes_ce_blk
ghash_ce 24576 0
gf128mul 16384 1 ghash_ce
sha2_ce 20480 0
sha256_arm64 28672 1 sha2_ce
sha1_ce 20480 0
panfrost 69632 0
gpu_sched 45056 1 panfrost
meson_saradc 24576 0
industrialio 90112 1 meson_saradc
irq_meson_gpio 20480 0
pwm_meson 20480 1
meson_dw_hdmi 24576 0
meson_drm 61440 1 meson_dw_hdmi
meson_canvas 16384 1 meson_drm
dw_hdmi 53248 1 meson_dw_hdmi
cec 57344 1 dw_hdmi
drm_kms_helper 258048 4 meson_dw_hdmi,meson_drm,dw_hdmi
meson_rng 16384 0
rng_core 24576 1 meson_rng
cpufreq_dt 20480 0
leds_gpio 16384 0
drm 606208 7 gpu_sched,meson_dw_hdmi,meson_drm,drm_kms_helper,dw_hdmi,panfrost
ip_tables 32768 0
x_tables 45056 1 ip_tables
autofs4 49152 2
xhci_plat_hcd 20480 0
dwc2 249856 0
dwc3 151552 0
ulpi 20480 1 dwc3
udc_core 69632 2 dwc2,dwc3
rtc_hym8563 20480 0
meson_gxl 20480 0
realtek 24576 0
dwmac_generic 16384 0
dwc3_meson_g12a 24576 0
meson_gx_mmc 24576 0
xhci_pci 24576 0
igb 237568 0
xhci_hcd 290816 2 xhci_pci,xhci_plat_hcd
i2c_meson 20480 0
mdio_mux_meson_g12a 16384 0
mdio_mux 16384 1 mdio_mux_meson_g12a
nvme 45056 2
nvme_core 110592 4 nvme
i2c_algo_bit 16384 1 igb
t10_pi 16384 1 nvme_core
usbcore 311296 4 xhci_hcd,dwc2,xhci_pci,xhci_plat_hcd
dwmac_meson8b 16384 0
stmmac_platform 24576 2 dwmac_meson8b,dwmac_generic
stmmac 204800 3 dwmac_meson8b,stmmac_platform,dwmac_generic
pcs_xpcs 20480 1 stmmac
phylink 45056 1 stmmac
of_mdio 20480 4 stmmac_platform,mdio_mux,stmmac,phylink
fixed_phy 16384 1 of_mdio
pwm_regulator 20480 1
libphy 151552 8 of_mdio,realtek,mdio_mux,stmmac,fixed_phy,meson_gxl,phylink,pcs_xpcs

root@tiger-roach:~# cat /proc/interrupts
CPU0 CPU1 CPU2 CPU3
9: 0 0 0 0 GICv2 25 Level vgic
11: 0 0 0 0 GICv2 30 Level kvm guest ptimer
12: 0 0 0 0 GICv2 27 Level kvm guest vtimer
13: 4151 2344 3022 4003 GICv2 26 Level arch_timer
16: 0 0 0 0 GICv2 89 Edge dw_hdmi_top_irq, ff600000.hdmi-tx
20: 1994 0 0 0 GICv2 225 Edge ttyAML0
21: 28 0 0 0 GICv2 227 Edge ff805000.i2c
23: 2 0 0 0 GICv2 232 Edge ff809000.adc
26: 0 0 0 0 GICv2 35 Edge meson
29: 1317 0 0 0 GICv2 222 Edge ffe05000.sd
30: 762 0 0 0 GICv2 223 Edge ffe07000.mmc
32: 0 0 0 0 GICv2 194 Level panfrost-job
33: 0 0 0 0 GICv2 193 Level panfrost-mmu
34: 3 0 0 0 GICv2 192 Level panfrost-gpu
35: 0 0 0 0 GICv2 31 Level arm-pmu
37: 0 0 0 0 GICv2 255 Level PCIe PME, aerdrv
43: 15 0 0 0 PCI-MSI 2621440 Edge nvme0q0
44: 951 0 0 0 PCI-MSI 2621441 Edge nvme0q1
45: 809 0 0 0 PCI-MSI 2621442 Edge nvme0q2
46: 605 0 0 0 PCI-MSI 2621443 Edge nvme0q3
47: 544 0 0 0 PCI-MSI 2621444 Edge nvme0q4
48: 38 0 0 0 PCI-MSI 1572864 Edge xhci_hcd
58: 0 0 0 0 GICv2 63 Level ff400000.usb, ff400000.usb
59: 32 0 0 0 GICv2 62 Level xhci-hcd:usb3
IPI0: 1253 1491 2091 2098 Rescheduling interrupts
IPI1: 297 306 756 385 Function call interrupts
IPI2: 0 0 0 0 CPU stop interrupts
IPI3: 0 0 0 0 CPU stop (for crash dump) interrupts
IPI4: 0 0 0 0 Timer broadcast interrupts
IPI5: 0 0 0 0 IRQ work interrupts
IPI6: 0 0 0 0 CPU wake-up interrupts
Err: 0

and eth0 is dead.

M.
--
Jazz is not dead. It just smells funny...