Reduce SPI broken reset warning (in kernel messages)

[greenbreakfast]

Context

OpenWRT 23.05 branch

Motivation

Why are we doing this? What use cases does it support? What problems does it solve? What is the expected outcome?

Goal: Decreasing developer friction

The Omega2+/2S+ features a flash chip that requires a broken-flash-reset flag to be set in the DTS (Device Tree Specification), https://github.com/openwrt/openwrt/blob/openwrt-23.05/target/linux/ramips/dts/mt7628an_onion_omega2p.dts#L9C2-L9C20

(More details on the the broken flash reset issue in this Onion Community post and this Github issue comment)

This broken-flash-reset flag causes the kernel to output a large message during device boot. This message can cause undue confusion - making users think there's an error when this is just a warning message.

Description

A clear and concise description of what you want to happen.
It should be reasonably clear how the improvement would be implemented.

Current behaviour: the bootlog outputs a large warning message like this (from OnionIoT/OpenWRT-Packages#62 (comment)):

[ 0.355272] spi-mt7621 10000b00.spi: sys_freq: 193333333
[ 0.384812] ------------[ cut here ]------------
[ 0.389526] WARNING: CPU: 0 PID: 1 at drivers/mtd/spi-nor/core.c:2863 spi_nor_init+0x17c/0x184
[ 0.398363] enabling reset hack; may not recover from unexpected reboots
[ 0.405180] Modules linked in:
[ 0.408287] CPU: 0 PID: 1 Comm: swapper Not tainted 5.15.150 #0
[ 0.414310] Stack : 00000000 00000000 80c23944 80870000 806c0000 80613540 80c3b280 806b9e03
[ 0.422843] 808733b4 00000001 809c8c7c 80061a48 8060cc5c 00000001 80c23900 b28cf387
[ 0.431370] 00000000 00000000 80613540 80c23798 ffffefff 00000000 00000000 ffffffea
[ 0.439897] 00000000 80c237a4 00000049 806c0298 80870000 00000009 00000000 80378cf4
[ 0.448411] 00000009 809c8c7c 80650000 80e34400 00000018 8033b394 00000000 80870000
[ 0.456933] ...
[ 0.459422] Call Trace:
[ 0.461909] [<8000702c>] show_stack+0x28/0xf0
[ 0.466364] [<80026228>] __warn+0x9c/0x124
[ 0.470547] [<8002633c>] warn_slowpath_fmt+0x8c/0xac
[ 0.475595] [<80378cf4>] spi_nor_init+0x17c/0x184
[ 0.480387] [<80379588>] spi_nor_scan+0x7a4/0xba0
[ 0.485171] [<8037a2c8>] spi_nor_probe+0x94/0x310
[ 0.489963] [<8034c8ac>] really_probe.part.0+0xac/0x354
[ 0.495279] [<8034cde0>] driver_probe_device+0x4c/0x154
[ 0.500599] [<8034d438>] __device_attach_driver+0xd0/0x15c
[ 0.506176] [<8034a524>] bus_for_each_drv+0x70/0xb0
[ 0.511171] [<8034d15c>] __device_attach+0xe0/0x180
[ 0.516130] [<8034b7f8>] bus_probe_device+0xa0/0xbc
[ 0.521096] [<80347f9c>] device_add+0x3e4/0x8e0
[ 0.525709] [<80384bd4>] __spi_add_device+0x90/0x178
[ 0.530773] [<80384d1c>] spi_add_device+0x60/0x9c
[ 0.535556] [<803850e8>] of_register_spi_device+0x21c/0x364
[ 0.541229] [<80385808>] spi_register_controller+0x5d8/0x7dc
[ 0.546981] [<803882d8>] mt7621_spi_probe+0x168/0x220
[ 0.552130] [<8034f18c>] platform_probe+0x50/0xa4
[ 0.556923] [<8034c8ac>] really_probe.part.0+0xac/0x354
[ 0.562242] [<8034cde0>] driver_probe_device+0x4c/0x154
[ 0.567553] [<8034d570>] __driver_attach+0xac/0x1ac
[ 0.572518] [<8034a478>] bus_for_each_dev+0x68/0xa4
[ 0.577482] [<8034bacc>] bus_add_driver+0x150/0x238
[ 0.582450] [<8034deb4>] driver_register+0x98/0x154
[ 0.587409] [<80000638>] do_one_initcall+0x50/0x1b4
[ 0.592377] [<8074a0e0>] kernel_init_freeable+0x1d0/0x26c
[ 0.597875] [<80579600>] kernel_init+0x20/0x108
[ 0.602511] [<80002478>] ret_from_kernel_thread+0x14/0x1c
[ 0.608005]
[ 0.609558] ---[ end trace 542a901b67c5a14f ]---
[ 0.614747] spi-nor spi0.0: w25q256 (32768 Kbytes)
[ 0.619722] 4 fixed-partitions partitions found on MTD device spi0.0
[ 0.626287] OF: Bad cell count for /palmbus@10000000/spi@b00/flash@0/partitions
[ 0.633792] OF: Bad cell count for /palmbus@10000000/spi@b00/flash@0/partitions
[ 0.641739] OF: Bad cell count for /palmbus@10000000/spi@b00/flash@0/partitions
[ 0.649213] OF: Bad cell count for /palmbus@10000000/spi@b00/flash@0/partitions

Desired outcome: a much smaller warning message

Method: apply a patch to reduce the warning to a single line
https://github.com/plan44/plan44-feed/blob/main/p44b-onion/p44build/global-patches/256-prevent-trace-for-broken-flash-reset.diff

Alternatives Considered

N/A

Additional Resources

See @plan44's solution here: https://github.com/plan44/plan44-feed/blob/main/p44b-onion/p44build/global-patches/256-prevent-trace-for-broken-flash-reset.diff
More context here: OnionIoT/OpenWRT-Packages#62 (comment)

Deliverables

• New patch and changes as needed to the openwrt-23.05 branch of the OnionIoT/openwrt-buildsystem-wrapper repo
• Screenshots/command line output demonstrating reduced SPI warning in kernel log

[greenbreakfast]

Patch applied in release: https://github.com/OnionIoT/openwrt-buildsystem-wrapper/releases/tag/23.05.3-20240609

Tested firmware (built with imagebuilder from this release) on device and not seeing broken reset warnings:

Fix added to Omega2 firmware in OnionIoT/OpenWRT-Packages release 23.05.3-20240610. All future firmware (23.05 and beyond) will include this fix.

Closing this issue. If anyone experiences different behaviour, feel free to reopen