Bug#1002850: Re (2): Bug#1002850: udev fails to create a symlink for a SDHC card connected to a Sharp Mebius laptop.

[peter at easthope.ca]

Hello Michael,

From: Michael Biebl <biebl at debian.org>
Date: Thu, 30 Dec 2021 08:43:32 +0100
> What procedures?

In essence I followed the procedure to attach a SYMLINK name to the 
SDHC card as described here.  https://wiki.debian.org/udev

The salient step is to make an effective udev rule.  More details are 
in the message at debian-user, linked in the preceeding message 10.
The result is these two different rules; each being effective in the 
desktop system.

KERNEL=="sd?1", ATTR{size}=="7434240", SYMLINK+="GRNSD", \
 OWNER="peter", GROUP="users"
 
KERNEL=="sd?1", ENV{ID_SERIAL_SHORT}=="0201202010201000", SYMLINK+="GRNSD", \
 OWNER="peter", GROUP="peter"

Neither of these produces the SYMLINK in Debian 11 on the Sharp Mebius.

> What symlink? Please be more specific.
> Have you created custom udev rules or what?

Yes, certainly the rules above were defined in the systems.  Described 
in detail in the message to debian-user.   Here is the link again.
https://lists.debian.org/debian-user/2021/12/msg00937.html

The SYMLINK name "GRNSD", is visible in each rule above.  The 
essential concept is that 'KERNEL=="sd?1", ATTR{size}=="7434240"' in 
the first rule and 
'KERNEL=="sd?1", ENV{ID_SERIAL_SHORT}=="0201202010201000"' in the 
second rule identify the SDHC.  Then 'SYMLINK+="GRNSD"' connects the 
name to the device. Note that each rule should accomplish the same 
result.  Only one rule should be required. The rule using SERIAL 
avoids the risk of ambiguity in the unlikely case of two devices 
containing parts exactly the same size.  That is 7434240 byte parts.

In Debian 11 on the generic desktop machine, all works as expected.
Neither rule produces the symlink in Debian 11 on the Sharp Mebius.
For background, I've used rules containing ATTR{size} in various 
desktop and laptop machines through several Debian releases.  
According to Wikipedia, the initial release of udev was in 2003. In 
Debian I guess udev first appeared after Woody, Debian 3. I don't 
recall specifically but I've used udev successfully for about a 
decade.  This is the first instance of failure.

Before submitting the message to debian-user I had hoped that others 
might have noticed a related problem.  Apparently not.  Therefore the 
next step should be a debug procedure.  Maybe you have an idea or tip 
before I try debugging.  =8~)

Thanks,                            ... Peter E.


 
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