RE: saa7134 and EIO — Video for Linux


] -----Original Message-----
] From: video4linux-list-admin@xxxxxxxxxx
] [mailto:video4linux-list-admin@xxxxxxxxxx] On Behalf Of Gerd Knorr
] Sent: Monday, March 31, 2003 7:37 PM
] To: video4linux-list@xxxxxxxxxx
] Subject: Re: saa7134 and EIO
]
]
] "greg" <greg.wickham@xxxxxxxxxxxxx> writes:
]
] >  - After an indeterminate period of time VIDIOC_DQBUF returns -EIO.
] >    Tracing this through it is caused by a buffer being set into
] >    STATE_ERROR due to a timeout (BUFFER_TIMEOUT) expiring.
] >    I have no idea why this occurs.
]
] The saa7134 failed to deliver a IRQ within the expected timeframe.
]
] >  - Once an EIO error occurs no frames can be captured
] (ever.. more EIO
] > errors)
]
] Sometimes I/O errors happens with a bad signal.  But in that
] case the saa7134 will capture frames again once the signal is
] better instead of refusing to do anything until power-cycled.

Confirmed. I have a camera directly attached and when that's powered
off EIO errors abound. Re-enabling the camera, all returns to normal.

] I've seen several reports on this already, but it didn't
] happen so far happens on any of my my systems, I have no idea
] what this might be ...
]
] Any error messages in the syslog?  Does the card still
] produce any IRQs when locked (check /proc/interrupts)?

No non-debug video specific messages in syslog.

/proc/interrupts do not increment

Re-installed saa7134 with irq_debug=2 and there were no
irq debug messages logged (as expected).

What sort of diagnostics can be done to determine if the
card is in a sane state?

   -Greg

]   Gerd
]
] --
] Michael Moore for president!

--
Dr. Greg Wickham         GrangeNet Network Operations Manager
Phone: +61 2 6222 3552                         AARNet Pty Ltd
Mob : +61 4 0785 4566                 Australian Academic and
Email: greg.wickham@xxxxxxxxxxxxx            Research Network