em28xx submit of urb 0 failed (error=-27)

em28xx submit of urb 0 failed (error=-27)

[Antti Palosaari]

Do you have any idea about that bug?
kernel: submit of urb 0 failed (error=-27)

https://bugzilla.kernel.org/show_bug.cgi?id=72891

I have seen it recently very often when I try start streaming DVB. When 
it happens, device is unusable. I have feeling that it could be coming 
from recent 28xx big changes where it was modularised. IIRC I reported 
that at the time and Mauro added error number printing to log entry. 
Anyhow, it is very annoying and occurs very often. And people have 
started pinging me as I have added very many DVB devices to em28xx.

regards
Antti


-- 
http://palosaari.fi/

Re: em28xx submit of urb 0 failed (error=-27)

[Antti Palosaari]

I just ran blind scan using w_scan and it interrupted scanning, with 
following error (ioctl DMX_SET_FILTER failed: 27 File too large).

602000: (time: 00:58.973)
         (0.308sec): SCL (0x1F)
         (0.308sec) signal
         (0.308sec) lock
         signal ok:	QAM_AUTO f = 602000 kHz I999B8C999D999T999G999Y999 
(0:0:0)
         initial PAT lookup..
start_filter:1644: ERROR: ioctl DMX_SET_FILTER failed: 27 File too large

regards
Antti


On 06/12/2014 03:23 AM, Antti Palosaari wrote:
> Do you have any idea about that bug?
> kernel: submit of urb 0 failed (error=-27)
>
> https://bugzilla.kernel.org/show_bug.cgi?id=72891
>
> I have seen it recently very often when I try start streaming DVB. When
> it happens, device is unusable. I have feeling that it could be coming
> from recent 28xx big changes where it was modularised. IIRC I reported
> that at the time and Mauro added error number printing to log entry.
> Anyhow, it is very annoying and occurs very often. And people have
> started pinging me as I have added very many DVB devices to em28xx.
>
> regards
> Antti
>
>


-- 
http://palosaari.fi/

Re: em28xx submit of urb 0 failed (error=-27)

[Mauro Carvalho Chehab]

Em Thu, 12 Jun 2014 03:37:26 +0300
Antti Palosaari <crope@iki.fi> escreveu:

> I just ran blind scan using w_scan and it interrupted scanning, with 
> following error (ioctl DMX_SET_FILTER failed: 27 File too large).
> 
> 602000: (time: 00:58.973)
>          (0.308sec): SCL (0x1F)
>          (0.308sec) signal
>          (0.308sec) lock
>          signal ok:	QAM_AUTO f = 602000 kHz I999B8C999D999T999G999Y999 
> (0:0:0)
>          initial PAT lookup..
> start_filter:1644: ERROR: ioctl DMX_SET_FILTER failed: 27 File too large
> 
> regards
> Antti
> 
> 
> On 06/12/2014 03:23 AM, Antti Palosaari wrote:
> > Do you have any idea about that bug?
> > kernel: submit of urb 0 failed (error=-27)
> >
> > https://bugzilla.kernel.org/show_bug.cgi?id=72891
> >
> > I have seen it recently very often when I try start streaming DVB. When
> > it happens, device is unusable. I have feeling that it could be coming
> > from recent 28xx big changes where it was modularised. IIRC I reported
> > that at the time and Mauro added error number printing to log entry.
> > Anyhow, it is very annoying and occurs very often. And people have
> > started pinging me as I have added very many DVB devices to em28xx.

Well, according with USB documentation (Documentation/usb/URB.txt),
EFBIG means:
- Too many requested ISO frames

Perhaps the logic that calculates the number of URBs has a bug. In
the past, the URB size was hardcoded. Nowadays, em28xx dynamically
calculate it based on the USB descriptors, and the endpoints found.

>From what I know, different versions of em28xx chips have different
max limits. We need to identify on what chip version this error is
occurring, and reduce the number of ISOC frames there (with will
reduce the max bandwidth supported by such chip).

Regards,
Mauro

Re: em28xx submit of urb 0 failed (error=-27)

[Antti Palosaari]

On 06/14/2014 03:45 PM, Mauro Carvalho Chehab wrote:
> Em Thu, 12 Jun 2014 03:37:26 +0300
> Antti Palosaari <crope@iki.fi> escreveu:
>
>> I just ran blind scan using w_scan and it interrupted scanning, with
>> following error (ioctl DMX_SET_FILTER failed: 27 File too large).
>>
>> 602000: (time: 00:58.973)
>>           (0.308sec): SCL (0x1F)
>>           (0.308sec) signal
>>           (0.308sec) lock
>>           signal ok:	QAM_AUTO f = 602000 kHz I999B8C999D999T999G999Y999
>> (0:0:0)
>>           initial PAT lookup..
>> start_filter:1644: ERROR: ioctl DMX_SET_FILTER failed: 27 File too large
>>
>> regards
>> Antti
>>
>>
>> On 06/12/2014 03:23 AM, Antti Palosaari wrote:
>>> Do you have any idea about that bug?
>>> kernel: submit of urb 0 failed (error=-27)
>>>
>>> https://bugzilla.kernel.org/show_bug.cgi?id=72891
>>>
>>> I have seen it recently very often when I try start streaming DVB. When
>>> it happens, device is unusable. I have feeling that it could be coming
>>> from recent 28xx big changes where it was modularised. IIRC I reported
>>> that at the time and Mauro added error number printing to log entry.
>>> Anyhow, it is very annoying and occurs very often. And people have
>>> started pinging me as I have added very many DVB devices to em28xx.
>
> Well, according with USB documentation (Documentation/usb/URB.txt),
> EFBIG means:
> - Too many requested ISO frames
>
> Perhaps the logic that calculates the number of URBs has a bug. In
> the past, the URB size was hardcoded. Nowadays, em28xx dynamically
> calculate it based on the USB descriptors, and the endpoints found.
>
>  From what I know, different versions of em28xx chips have different
> max limits. We need to identify on what chip version this error is
> occurring, and reduce the number of ISOC frames there (with will
> reduce the max bandwidth supported by such chip).

I tested these as having that issue:
em28178 PCTV tripleStick (292e)
em2874 MaxMedia UB425-TC
em2884 PCTV QuatroStick nano (520e)

Bug report mentions also:
em28174 PCTV nanoStick T2 (290e)
em28178 PCTV DVB-S2 Stick (461e)

So it must effect huge amount (if not all) of different em28xx chips 
used for DTV.


regards
Antti

-- 
http://palosaari.fi/