Bug 87414

Summary:	error opening ATTR{/sys/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.3/1-1.3:1.0/power/control} for writing
Product:	libfprint	Reporter:	Rex Dieter <rdieter>
Component:	libfprint	Assignee:	libfprint-bugs
Status:	RESOLVED FIXED	QA Contact:
Severity:	normal
Priority:	medium	CC:	zbyszek
Version:	unspecified	Keywords:	patch
Hardware:	Other
OS:	All
See Also:	https://bugzilla.redhat.com/show_bug.cgi?id=950205
Whiteboard:
i915 platform:		i915 features:
Attachments:	proof-of-concept patch to add TEST=power/control" to udev rules

Description Rex Dieter 2014-12-17 13:38:44 UTC

Created attachment 110952 [details] [review]
proof-of-concept patch to add TEST=power/control" to udev rules

Per downstream report,
https://bugzilla.redhat.com/show_bug.cgi?id=950205

libfprint udev rules try to set ATTR{power/control} without testing for existence first with TEST=="power/control".

Comment 1 Rex Dieter 2015-01-05 15:49:55 UTC

ping?

Comment 2 Rex Dieter 2015-01-21 15:28:43 UTC

another couple weeks, ping, feedback on patch please.

Comment 3 Bastien Nocera 2015-01-28 11:55:19 UTC

(In reply to Rex Dieter from comment #2)
> another couple weeks, ping, feedback on patch please.

Something tested would be better. None of the fingerprint readers I have have that problem. I'd also need to know why those devices don't have power control sysfs files.

Comment 4 Zbigniew Jedrzejewski-Szmek 2015-01-28 13:30:57 UTC

When the kernel does not detect or have support for power control.

FWIW, it the pattern that existing systemd (and many other) rules use, see 42-usb-hid-pm.rules.

Comment 5 Bastien Nocera 2015-01-28 15:31:08 UTC

commit 79d79c3c875d41379eae418157a8254e87641f85
Author: Rex Dieter <rdieter@math.unl.edu>
Date:   Wed Dec 17 07:27:15 2014 -0600

    lib: Test before applying power saving udev rules
    
    add TEST=="power/control"... to test for the presence of the file
    before setting it.
    
    See https://bugzilla.redhat.com/show_bug.cgi?id=950205
    
    https://bugs.freedesktop.org/show_bug.cgi?id=87414

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