Re: hard-to-reproduce bugs (was: plugged in thumb drive, which disconnected another USB drive)

2015-03-16 Thread Henrique de Moraes Holschuh
On Mon, Mar 16, 2015, at 00:16, Mike Kupfer wrote:
 Chris Bannister wrote:
  On Thu, Mar 12, 2015 at 09:04:51AM -0700, Mike Kupfer wrote:
   - Do I need to have a reproducible test case before opening a bug?
  
  If it is not reproducible, then how does one go about fixing it?
 
 I deal with hard-to-reproduce bugs in my day job fairly frequently.
 Sometimes I'm able to suggest refinements to the test case to make the
 problem easier to reproduce.  Sometimes I can tell the submitter what
 additional information to gather the next time the problem occurs.
 Sometimes the bug report sits idle for awhile as I wait for additional
 reports and additional clues.  In theory I can provide a special debug
 binary in the hopes of getting more information, though in practice I
 can't remember the last time I did this.  Sometimes I just find where a
 particular message is generated and poke through the source code to see
 if any causes leap out at me.
 
 I don't mean to suggest that I expect Debian package maintainers to do
 all that.  I asked because I've had mixed results asking support
 questions on this list, and I'm not sure what the cultural norms are in
 Debian for filing a formal bug report.

Fair enough.  Anyway, in this specific case, it is likely caused by the
hardware layer: it really looks like what would happen if the IOMEGA
device was subject to a sudden and short-term power loss/drop for
whatever reason when you plugged the other USB device on the same hub.

I don't think it is worth reporting it as a kernel bug, unless you have
enough details to show it was bad behavior on the USB host side, or a
bug in the available power allocation done by the kernel before it
decides whether it can activate the new USB device endpoints or not.

Also, IMHO, you should get rid of that USB hub and connect important
devices directly to the motherboard USB ports, using a proper USB cable
(and finding a non-substandard USB cable might be more challenging than
expected).

I won't go into details unless people around here are very interested on
the specifics.   But since it starts with way too many USB devices and
cables do not implement the USB specification properly, and goes
downhill from there, it is not likely to be very helpful.

-- 
  One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie. -- The Silicon Valley Tarot
  Henrique de Moraes Holschuh h...@debian.org


-- 
To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org 
with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Archive: 
https://lists.debian.org/1426530586.2678812.241124985.3f5c5...@webmail.messagingengine.com



hard-to-reproduce bugs (was: plugged in thumb drive, which disconnected another USB drive)

2015-03-15 Thread Mike Kupfer
Chris Bannister wrote:

 On Thu, Mar 12, 2015 at 09:04:51AM -0700, Mike Kupfer wrote:
  - Do I need to have a reproducible test case before opening a bug?
 
 If it is not reproducible, then how does one go about fixing it?

I deal with hard-to-reproduce bugs in my day job fairly frequently.
Sometimes I'm able to suggest refinements to the test case to make the
problem easier to reproduce.  Sometimes I can tell the submitter what
additional information to gather the next time the problem occurs.
Sometimes the bug report sits idle for awhile as I wait for additional
reports and additional clues.  In theory I can provide a special debug
binary in the hopes of getting more information, though in practice I
can't remember the last time I did this.  Sometimes I just find where a
particular message is generated and poke through the source code to see
if any causes leap out at me.

I don't mean to suggest that I expect Debian package maintainers to do
all that.  I asked because I've had mixed results asking support
questions on this list, and I'm not sure what the cultural norms are in
Debian for filing a formal bug report.

regards,
mike


-- 
To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org 
with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Archive: https://lists.debian.org/29201.1426475794@allegro.localdomain