Bug 28596 - Please enable the W1-gpio soft driver
Summary: Please enable the W1-gpio soft driver
Status: RESOLVED FIXED
Alias: None
Product: Mageia
Classification: Unclassified
Component: RPM Packages (show other bugs)
Version: 8
Hardware: All Linux
Priority: Normal enhancement
Target Milestone: ---
Assignee: Kernel and Drivers maintainers
QA Contact:
URL:
Whiteboard:
Keywords:
Depends on: 28610
Blocks:
  Show dependency treegraph
 
Reported: 2021-03-14 19:04 CET by Jybz
Modified: 2021-04-05 20:30 CEST (History)
0 users

See Also:
Source RPM: kernel
CVE:
Status comment:


Attachments

Description Jybz 2021-03-14 19:04:46 CET
Hello,
not all arm board embedded an "hard" w1 (also named one-wire, dallas, ...) module.
Many modules like temperature probe ds18b20 use that protocol.

There exists a soft driver already present in the kernel, W1_GPIO .
Comment 1 Thomas Backlund 2021-03-14 19:31:32 CET
enabled in svn for Mga8 and Cauldron so it will be part of next kernel builds
Comment 2 Lewis Smith 2021-03-14 21:08:24 CET
Thanks tmb for an instant response.
@Jybz : if the next kernel provides what you asked for, please close this bug resolved/fixed.

CC: (none) => lewyssmith

Comment 3 Thomas Backlund 2021-03-18 14:51:24 CET
This change is now in 5.11.7-1 kernels in Cauldron and 5.10.24-1 kernels currently in mga7 and mga8 updates_testing heading for validation:

https://bugs.mageia.org/show_bug.cgi?id=28610

Assignee: bugsquad => kernel
Depends on: (none) => 28610

Comment 4 Jybz 2021-03-19 12:43:34 CET
Perfect :
> Mageia release 8 (Official) for armv7hl
> Kernel 5.10.24-desktop-1.mga8 on a Dual-processor armv7l / ttyS0
> localhost login: 

> [root@localhost ~]# modprobe w1-gpio
> [   80.915414] Driver for 1-wire Dallas network protocol.

But... Without modifying the dtb overlay (what I don't know how it works and if it is suitable with grub2-efi + Mageia ), I don't know neither how using it with /sys/class/bus/w1 . The doc I found looks obscure.

:'(

I try after lunch.
Lewis Smith 2021-03-19 20:13:01 CET

CC: lewyssmith => (none)

Comment 5 Jybz 2021-03-19 20:38:46 CET
Still unable, but I dig further.

I was looking for dynamically loading device tree overlays, and found that it is not set on Mageia.

cat /boot/config-5.10.24-desktop-1.mga8 | grep CONFIG_OF_OVERLAY
# CONFIG_OF_OVERLAY is not set

Overlays look important for two reason :
- the lack of BIOS and the GPIO that computers doesn't have
- (unsure) our boot process is not (always/totaly) using the Raspberry logic (with config.txt read by their private bootloader).

But adding stuff over stuff, I'm not sure, won't we have a overweighted kernel ?
Comment 6 Thomas Backlund 2021-03-31 10:53:44 CEST
OF_OVERLAY is now enabled in svn for next Cauldron kernel build, 
and for Mga 7 / Mga 8 in kernel-5.10.27-1 that is now in updates_testing
Comment 7 Thomas Backlund 2021-04-03 15:39:23 CEST

Updates for this issue has been pushed to the Mageia Updates repository.

- arm(64): enable W1_MASTER_GPIO (mga#28596)
http://advisories.mageia.org/MGASA-2021-0151.html

- arm: enable OF_OVERLAY (mga#28596)
https://advisories.mageia.org/MGASA-2021-0174.html

Status: NEW => RESOLVED
Resolution: (none) => FIXED

Comment 8 Jybz 2021-04-05 20:30:58 CEST
Thank you tmb!

I tried today only (I couldn't earlier), but I don't meet the expected behavior for overlay.

I can read here : https://www.96boards.org/documentation/consumer/dragonboard/dragonboard410c/guides/dt-overlays.md.html
> When configfs has been mounted properly, that directory should have been populated with subdirectories /sys/kernel/config/device-tree/overlays

On my side :
> lsmod | grep conf
>   configfs               36864  1
> mount -l | grep conf
>   configfs on /sys/kernel/config type configfs (rw,nosuid,nodev,noexec,relatime)
> lsmod | grep over
> modprobe overlay
> lsmod | grep over
>   overlay                94208  0
> ls -lsah /sys/kernel/config
>   total 0
>   0 drwxr-xr-x  2 root root 0 Apr  5 16:17 ./
>   0 drwxr-xr-x 11 root root 0 Apr  5 16:17 ../

I can't create the subdirs my own :
> mkdir -p /sys/kernel/config/device-tree
>   mkdir: cannot create directory �‘/sys/kernel/config/device-tree�’: Operation not permitted

dmesg shows nothing after modprobe overlay.

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