On 2018-11-14 14:23, Hans Verkuil wrote:
On 11/14/18 14:00, Torbjorn Jansson wrote:
<snip>
since there now is a patch that appears to be working and fixing this problem
i'd like to ask for some troubleshooting advice with another cec issue i have
that i haven't figured out why it is happening and exactly whats causing it.
i'm not sure if it is a hardware issue or a software issue or both.
this is what is happening:
i have a script that polls the tv for current status by running:
cec-ctl --to=0 --give-device-power-status
after a fresh reboot this works fine for a while then sometime later it stops
working and errors with:
-
# cec-ctl --to=0 --give-device-power-status
Driver Info:
Driver Name : pulse8-cec
Adapter Name : serio0
Capabilities : 0x0000003f
Physical Address
Logical Addresses
Transmit
Passthrough
Remote Control Support
Monitor All
Driver version : 4.18.16
Available Logical Addresses: 1
Physical Address : 1.4.0.0
Logical Address Mask : 0x0800
CEC Version : 2.0
Vendor ID : 0x000c03
Logical Addresses : 1 (Allow RC Passthrough)
Logical Address : 11 (Playback Device 3)
Primary Device Type : Playback
Logical Address Type : Playback
All Device Types : Playback
RC TV Profile : None
Device Features :
None
Transmit from Playback Device 3 to TV (11 to 0):
CEC_MSG_GIVE_DEVICE_POWER_STATUS (0x8f)
Sequence: 119437 Tx Timestamp: 865389.535s
Tx, Error (1), Max Retries
-
once this happens i can never get back any status and also running:
cec-ctl -M
gives me a lot of:
Transmitted by Playback Device 3 to TV (11 to 0):
CEC_MSG_GIVE_DEVICE_POWER_STATUS (0x8f)
Tx, Error (1), Max Retries
once for every run of my status checking script.
i know polling like this is not the best option and a better way would be to
listen for events and then take action when status changes but that's not
easily doable with what i need it for.
anyway, once i start getting the above errors when i poll it will not give me
back any good status any more (everything errors out)
also sending commands to tv to turn on or off like:
cec-ctl --to=0 --image-view-on
or
cec-ctl --to=0 --standby
doesn't work.
BUT if i remove power to tv and wait for standby led to go out completely then
power it back on i can use above two commands to turn on/off the tv even when
they return errors and i still can't poll for current status.
so even with the errors always returned at this stage the on/off commands still
gets sent and works.
do you think this behavior is a sw or hw issue or both?
Does 'cec-ctl --to=0 --give-device-power-status' eventually fail even if the TV is
on all the time? Or does it only fail if the TV goes to standby or has been in
standby for a very long time?
good question, tv will go to standby by itself after some time and i can't have
the tv turned on for a few days in a row (not practical).
my gut feeling is that it happens after being in standby for a long time.
it may work fine for a day or two then it fails.
This error ('Tx, Error (1), Max Retries') indicates that the pulse-eight returns
transmit errors suggesting that the CEC line is locked (always high or low).
I did some more testing and i was able to somehow trigger the error state by
having one cec-ctl -M and one cec-ctl -S going at the same time but this is not
consistent (tested several times and was only able to get it to fail like this
once)
Also i tested to pull hdmi cable from tv when in error state and see if i could
reach other devices, tested with cec-ctl -S and it did display a some of my
other hdmi devices like amp & bd player.
So i guess my tv is to blame for locking up cec.
Maybe i'll just schedule something to cut power completely to tv during night
for a few hours.
if i'm not mistaken i could unplug usb cable to pulse8 cec adapter and reinsert
to make it work properly again (no errors and correct response like a fresh start)
but i'm not 100% sure of this.
when i tried it now i get a new kernel oops:
-
[866129.392139] usb 7-2: USB disconnect, device number 3
[866129.409568] cdc_acm 7-2:1.1: acm_start_wb - usb_submit_urb(write bulk)
failed: -19
[866129.409576] cdc_acm 7-2:1.1: acm_start_wb - usb_submit_urb(write bulk)
failed: -19
[866129.409635] WARNING: CPU: 10 PID: 1571 at drivers/media/cec/cec-adap.c:1243
Not a kernel oops, just a warning. The pulse-eight driver has a small bug
that causes this warning, but it does not affect the CEC behavior in any way.
I'll post a patch.
Ok so nothing to worry about then.
