On Wed, 25 Mar 2015 15:10:44 +0100
Florian Echtler [off-list ref] wrote:

Hello Dmitry,

On 25.03.2015 14:23, Dmitry Torokhov wrote:

quoted

On March 24, 2015 11:52:54 PM PDT, Florian Echtler [off-list ref] wrote:

quoted

Currently, I'm setting the interval for input_polldev to 10 ms.
However, with video data being retrieved at the same time, it's quite
possible that one iteration of poll() will take longer than that. Could
this ultimately be the reason? What happens if a new poll() call is
scheduled before the previous one completes?

This can't happen as we schedule the next poll only after current one completes.

Thanks - any other suggestions how to debug such a complete freeze? I
have the following options enabled in my kernel config:

CONFIG_LOCKUP_DETECTOR=y
CONFIG_HARDLOCKUP_DETECTOR=y
CONFIG_DETECT_HUNG_TASK=y
CONFIG_EARLY_PRINTK=y
CONFIG_EARLY_PRINTK_DBGP=y
CONFIG_EARLY_PRINTK_EFI=y

Unfortunately, even after the system is frozen for several minutes, I
never get to see a panic message. Maybe it's there on the console
somewhere, but the screen never switches away from X (and as mentioned
earlier, I think this bug can only be triggered from within X). Network
also freezes, so I don't think netconsole will help?

PSTORE + some EFI/ACPI mechanism, maybe?
http://lwn.net/Articles/434821/

However I have never tried that myself and I don't know if all the
needed bits are in linux already.

JFTR, on some embedded system I worked on in the past the RAM content
was preserved across resets and, after a crash, we used to dump the RAM
from a second stage bootloader (i.e. before lading another linux
instance) and then scrape the dump to look for the kernel messages, but
AFAIK this is not going to be reliable —or even possible— on a more
complex system.

Ciao,
   Antonio

-- 
Antonio Ospite
http://ao2.it

A: Because it messes up the order in which people normally read text.
   See http://en.wikipedia.org/wiki/Posting_style
Q: Why is top-posting such a bad thing?
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